update nginx.conf template server header setup

- add optional override lines for server header and to optionally remove X-Powered-By headers without needing to disable headers more nginx module which is required for other centmin mod features like redis nginx level caching & letsencrypt integration in vhosts created by addons/acmetool.sh https://community.centminmod.com/posts/55081/

config/nginx/nginx.conf

@@ -27,8 +27,19 @@ http {
 limit_req_zone $binary_remote_addr zone=xwplogin:16m rate=40r/m;
 #limit_conn_zone $binary_remote_addr zone=xwpconlimit:16m;
 
+# sets Centmin Mod headers via headers more nginx module
+# https://github.com/openresty/headers-more-nginx-module
+# don't remove the first 2 lines as centmin mod checks to see if they're 
+# missing and re-adds them anyway. Just uncomment the 3rd & 4th lines
+# which is used to override the Server header to what you want = nginx
+# and remove the X-Powered-By header + restart nginx service
+# do not disable headers more nginx module itself as it's required for
+# other centmin mod features like redis nginx level caching & letsencrypt
+# integration in vhosts created by addons/acmetool.sh
 more_set_headers "Server: nginx centminmod";
 more_set_headers "X-Powered-By: centminmod";
+#more_set_headers "Server: nginx";
+#more_clear_headers "X-Powered-By";
 
 # uncomment cloudflare.conf include if using cloudflare for
 # server and/or vhost site + setup cron job for command