Removed code that was used as test fix for a letsencrypt issue.

install/tpl/nginx_ispconfig.vhost.master

-server {
-	location ~ /\.well-known/acme-challenge/ {
-		root /usr/local/ispconfig/interface/acme/;
-		index index.html index.htm;
-		try_files $uri =404;
-	}
-}
 server {
         listen {vhost_port};
         listen [::]:{vhost_port} ipv6only=on;