nginx multiple server with subdomain not working

Question

I installed nginx on linux. I included my nginx conf file in default nginx.conf include /var/nginx/nginx.conf

in my /var/nginx/nginx.conf I have two server blocks

server {
    listen 80;
    listen 443 ssl http2;
    server_name dev.test.com;
    include /var/nginx/ssl.conf;

    keepalive_timeout   100;
    ignore_invalid_headers off;
    location / {
            proxy_pass http://serverbk;
    }
}
server {
    listen 80;
    server_name config.test.com;

    keepalive_timeout   100;
    ignore_invalid_headers off;
    location / {
            proxy_pass http://configbk;
    }
}

''' Problem is when I go for http://config.test.com it gives me 307 internal server redirect to https://dev.test.com

I am not able to understand why redirection is happening.

in access logs $server_name is coming as dev.test.com while $host is coming as config.test.com

output of nginx -T

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
        worker_connections 768;
        # multi_accept on;
}

http {

        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        # server_tokens off;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # SSL Settings
        ##

        #ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
        #ssl_prefer_server_ciphers on;

        ##
        # Logging Settings
        ##
        log_format upstreamlog '[$time_local] $remote_addr - $remote_user - $server_name $host to: $upstream_addr: $request $status upstream_response_time $upstream_response_time msec $msec request_time $request_time';

        access_log /var/log/nginx/access.log upstreamlog;
        error_log /var/log/nginx/error.log;

        ##
        # Gzip Settings
        ##

        gzip on;

        # gzip_vary on;
        # gzip_proxied any;
        # gzip_comp_level 6;
        # gzip_buffers 16 8k;
        # gzip_http_version 1.1;
        # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

        ##
        # Virtual Host Configs
        ##

        include /etc/nginx/conf.d/*.conf;
        #include /etc/nginx/sites-enabled/*;

        include /var/nginx/nginx.conf;
}

#mail {
#       # See sample authentication script at:
#       # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
#
#       # auth_http localhost/auth.php;
#       # pop3_capabilities "TOP" "USER";
#       # imap_capabilities "IMAP4rev1" "UIDPLUS";
#
#       server {
#               listen     localhost:110;
#               protocol   pop3;
#               proxy      on;
#       }
#
#       server {
#               listen     localhost:143;
#               protocol   imap;
#               proxy      on;
#       }
#}

# configuration file /etc/nginx/modules-enabled/50-mod-http-geoip.conf:
load_module modules/ngx_http_geoip_module.so;

# configuration file /etc/nginx/modules-enabled/50-mod-http-image-filter.conf:
load_module modules/ngx_http_image_filter_module.so;

# configuration file /etc/nginx/modules-enabled/50-mod-http-xslt-filter.conf:
load_module modules/ngx_http_xslt_filter_module.so;

# configuration file /etc/nginx/modules-enabled/50-mod-mail.conf:
load_module modules/ngx_mail_module.so;

# configuration file /etc/nginx/modules-enabled/50-mod-stream.conf:
load_module modules/ngx_stream_module.so;

# configuration file /etc/nginx/mime.types:

types {
    text/html                             html htm shtml;
    text/css                              css;
    text/xml                              xml;
    image/gif                             gif;
    image/jpeg                            jpeg jpg;
    application/javascript                js;
    application/atom+xml                  atom;
    application/rss+xml                   rss;

    text/mathml                           mml;
    text/plain                            txt;
    text/vnd.sun.j2me.app-descriptor      jad;
    text/vnd.wap.wml                      wml;
    text/x-component                      htc;

    image/png                             png;
    image/tiff                            tif tiff;
    image/vnd.wap.wbmp                    wbmp;
    image/x-icon                          ico;
    image/x-jng                           jng;
    image/x-ms-bmp                        bmp;
    image/svg+xml                         svg svgz;
    image/webp                            webp;

    application/font-woff                 woff;
    application/java-archive              jar war ear;
    application/json                      json;
    application/mac-binhex40              hqx;
    application/msword                    doc;
    application/pdf                       pdf;
    application/postscript                ps eps ai;
    application/rtf                       rtf;
    application/vnd.apple.mpegurl         m3u8;
    application/vnd.ms-excel              xls;
    application/vnd.ms-fontobject         eot;
    application/vnd.ms-powerpoint         ppt;
    application/vnd.wap.wmlc              wmlc;
    application/vnd.google-earth.kml+xml  kml;
    application/vnd.google-earth.kmz      kmz;
    application/x-7z-compressed           7z;
    application/x-cocoa                   cco;
    application/x-java-archive-diff       jardiff;
    application/x-java-jnlp-file          jnlp;
    application/x-makeself                run;
    application/x-perl                    pl pm;
    application/x-pilot                   prc pdb;
    application/x-rar-compressed          rar;
    application/x-redhat-package-manager  rpm;
    application/x-sea                     sea;
    application/x-shockwave-flash         swf;
    application/x-stuffit                 sit;
    application/x-tcl                     tcl tk;
    application/x-x509-ca-cert            der pem crt;
    application/x-xpinstall               xpi;
    application/xhtml+xml                 xhtml;
    application/xspf+xml                  xspf;
    application/zip                       zip;

    application/octet-stream              bin exe dll;
    application/octet-stream              deb;
    application/octet-stream              dmg;
    application/octet-stream              iso img;
    application/octet-stream              msi msp msm;

    application/vnd.openxmlformats-officedocument.wordprocessingml.document    docx;
    application/vnd.openxmlformats-officedocument.spreadsheetml.sheet          xlsx;
    application/vnd.openxmlformats-officedocument.presentationml.presentation  pptx;

    audio/midi                            mid midi kar;
    audio/mpeg                            mp3;
    audio/ogg                             ogg;
    audio/x-m4a                           m4a;
    audio/x-realaudio                     ra;

    video/3gpp                            3gpp 3gp;
    video/mp2t                            ts;
    video/mp4                             mp4;
    video/mpeg                            mpeg mpg;
    video/quicktime                       mov;
    video/webm                            webm;
    video/x-flv                           flv;
    video/x-m4v                           m4v;
    video/x-mng                           mng;
    video/x-ms-asf                        asx asf;
    video/x-ms-wmv                        wmv;
    video/x-msvideo                       avi;
}

# configuration file /var/nginx/nginx.conf:

        upstream serverbk {
                server server1ip:30015;
                server server2ip:30015;
        }
        upstream configbk {
                server server1ip:30010;
                server server2ip:30010;
        }

    server {
        listen 80;
        listen       443 ssl http2;
        server_name dev.test.com;

        if ($scheme = http) {
                return 301 https://dev.test.com$request_uri;
        }

        ssl_password_file   /var/nginx/password.pass;
        ssl_certificate     /var/nginx/server.crt;
        ssl_certificate_key /var/nginx/server.rsa;
        include /var/nginx/ssl.conf;

        keepalive_timeout   100;
        ignore_invalid_headers off;

        location / {
            add_header X-debug-message "All" always;
            proxy_pass https://serverbk/;
            proxy_ssl_trusted_certificate /var/nginx/backend.server.pem;
            proxy_ssl_password_file    /var/nginx/password.pass;
            proxy_ssl_verify              off;
            proxy_buffer_size          128k;
            proxy_buffers              4 256k;
            proxy_busy_buffers_size    256k;
            include /var/nginx/proxy.conf;

        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html2;
        }
    }
    server {
        listen 80;
        server_name config.test.com;

        keepalive_timeout   100;
        ignore_invalid_headers off;
        location / {
                proxy_pass http://configbk;
        }
    }
# configuration file /var/nginx/ssl.conf:
ssl_session_timeout 1d;
ssl_session_cache shared:SSL:50m;
ssl_session_tickets off;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_prefer_server_ciphers on;

# configuration file /var/nginx/proxy.conf:
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_buffering off;
proxy_request_buffering off;
proxy_http_version 1.1;
proxy_intercept_errors on;