Add real_ip setting to nginx example.

ref)
https://docs.gitlab.com/omnibus/settings/nginx.html#configuring-gitlab-trusted_proxies-and-the-nginx-real_ip-module

lib/support/nginx/gitlab

@@ -38,6 +38,12 @@ server {
 
   ## See app/controllers/application_controller.rb for headers set
 
+  ## Real IP Module Config
+  ## http://nginx.org/en/docs/http/ngx_http_realip_module.html
+  real_ip_header X-Real-IP; ## X-Real-IP or X-Forwarded-For or proxy_protocol
+  real_ip_recursive off;    ## If you enable 'on'
+  set_real_ip_from YOUR_TRUSTED_ADDRESS; ## Replace this with something like 192.168.1.0/24
+
   ## Individual nginx logs for this GitLab vhost
   access_log  /var/log/nginx/gitlab_access.log;
   error_log   /var/log/nginx/gitlab_error.log;

lib/support/nginx/gitlab-ssl

@@ -82,6 +82,12 @@ server {
   ##
   # ssl_dhparam /etc/ssl/certs/dhparam.pem;
 
+  ## Real IP Module Config
+  ## http://nginx.org/en/docs/http/ngx_http_realip_module.html
+  real_ip_header X-Real-IP; ## X-Real-IP or X-Forwarded-For or proxy_protocol
+  real_ip_recursive off;    ## If you enable 'on'
+  set_real_ip_from YOUR_TRUSTED_ADDRESS; ## Replace this with something like 192.168.1.0/24
+
   ## Individual nginx logs for this GitLab vhost
   access_log  /var/log/nginx/gitlab_access.log;
   error_log   /var/log/nginx/gitlab_error.log;