Nginx – Image not display after using nginx

recently i change my web server from apache to nginx,
my site using using wordpress and use google drive wp media plugin to store image in google drive ,
after i change to nginx all image suddenly post images are not Display
honestly i dont know where to begin but there is .htaccess and php file on /wp-content/uploads/gdwpm_images
here is the .htaccess file

RewriteEngine on
RewriteBase /
RewriteCond %{QUERY_STRING} !^imgid= [NC]
RewriteRule ^(.*)$ wp-content/uploads/gdwpm_images/index.php?imgid=$1 [L,NC,QSA]

and here the index.php file

<?php
if (isset($_GET['imgid'])){
    $gdwpm_ekst_gbr = explode('.', $_GET['imgid']);
    if($gdwpm_ekst_gbr[1] == 'png' || $gdwpm_ekst_gbr[1] == 'gif' || $gdwpm_ekst_gbr[1] == 'bmp'){
        header("Content-Type: image/" . $gdwpm_ekst_gbr[1]);
    }else{
        header("Content-Type: image/jpg");
    }
    $gdurl = "https://docs.google.com/uc?id=" . $gdwpm_ekst_gbr[0] . "&export=view";
    @readfile($gdurl);
}
?>

i tried this:

# nginx configuration location / { if ($query_string !~ "^imgid="){ rewrite ^(.*)$ /wp-content/uploads/gdwpm_images/index.php?imgid=$1 break; } }

and this

location ~ /wp-content/uploads/gdwpm_images/index.php {
    if ($args ~* "^imgid=") {
        set $mid $1;
        set $args '';
        rewrite ^.*$ /wp-content/uploads/gdwpm_images/index.php?imgid=$1 permanent;
    }
}

nothing works, all image like

http://example.com/wp-content/uploads/gdwpm_images/0B73ed93lY08zZkXsDDkY5VFNSZjg.jpg 

return in 404, how is the correct rewrite rule for this
thanks

edit :
Server
Ubuntu 14.04.4 LTS (GNU/Linux 3.13.0-79-generic x86_64)
nginx version: nginx/1.4.6 (Ubuntu)
PHP 5.5.9-1ubuntu4.14 (fpm-fcgi)
cURL support enabled
cURL Information 7.35.0

#AUTOMATICALLY GENERATED - DO NO EDIT!

server {
    listen *:80;
    server_name example.com;

    access_log /var/log/nginx/examplecom.access.log;
    error_log /var/log/nginx/example.com.error.log;

    root /srv/examplecom;
    index index.html index.htm index.php;

    # This order might seem weird - this is attempted to match last if rules below fail.
location / {
    try_files $uri $uri/ /index.php?$args;
 }

location /wp-content/uploads/gdwpm_images {
if ($query_string !~ "^imgid=") {
    rewrite ^/(.*)$ /wp-content/uploads/gdwpm_images/index.php?imgid=$1 last;
}
}
# Add trailing slash to */wp-admin requests.
rewrite /wp-admin$ $scheme://$host$uri/ permanent;


# Directives to send expires headers and turn off 404 error logging.
location ~* ^.+\.(ogg|ogv|svg|svgz|eot|otf|woff|mp4|ttf|rss|atom|jpg|jpeg|gif|png|ico|zip|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf)$ {
       access_log off; log_not_found off; expires max;
}

location = /favicon.ico {
    log_not_found off;
    access_log off;
}
location = /robots.txt {
    allow all;
    log_not_found off;
    access_log off;
}
# Deny all attempts to access hidden files such as .htaccess, .htpasswd, .DS_Store (Mac).
# Keep logging the requests to parse later (or to pass to firewall utilities such as fail2ban)
location ~ /\. {
    deny all;
}
# Deny access to any files with a .php extension in the uploads directory
# Works in sub-directory installs and also in multisite network
# Keep logging the requests to parse later (or to pass to firewall utilities such as fail2ban)
location ~* /(?:uploads|files)/.*\.php$ {
    deny all;
}

    location ~ [^/]\.php(/|$) {

        try_files $uri =404;
fastcgi_split_path_info ^(.+\.php)(/.+)$;

        fastcgi_index index.php;
        include fcgi.conf;
        fastcgi_pass unix:/var/run/ajenti-v-php-fcgi-examplecom-php-fcgi-0.sock;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

    }

}

im using Ajenti web panel for my nginx server