include ACME challenge location snippet in NGINX template

ceod/model/templates/nginx_cloud_vhost_config.j2

@@ -19,6 +19,7 @@ server {
     proxy_pass http://{{ ip_address }};
   }
   include proxy_params;
+  include acme_challenge_params;
 
   access_log /var/log/nginx/member-{{ username }}-access.log;
   error_log /var/log/nginx/member-{{ username }}-error.log;