nginx/application: Hide server tokens per default

roles/nginx/application/templates/nginx.conf

@@ -21,7 +21,7 @@ http {
   tcp_nodelay on;
   keepalive_timeout 65;
   types_hash_max_size 2048;
-  # server_tokens off;
+  server_tokens off; # Hide Server Tokens like Version for Security
 
   # server_names_hash_bucket_size 64;
   # server_name_in_redirect off;