nginx: Added ACME redirect to main domain based on alias domain fix

This allows sites using redirect=proxy to still generate ACME
certificates by not passing the acme requests through to the proxy.

We should also consider using this for other features available such as
own error documents, SSI and custom directives.

Author: Judah MW

server/conf/nginx_vhost.conf.master

@@ -69,6 +69,16 @@ server {
         <tmpl_if name='exclude_own_hostname'>if ($http_host != "<tmpl_var name='exclude_own_hostname'>") { </tmpl_if>rewrite ^<tmpl_var name='rewrite_exclude'>(.*)$ <tmpl_var name='rewrite_target'>$2 <tmpl_var name='rewrite_type'>;<tmpl_if name='exclude_own_hostname'> }</tmpl_if>
 </tmpl_if>
 <tmpl_if name='use_proxy'>
+        ## no proxy for acme-challenge
+        location ^~ /.well-known/acme-challenge/ {
+            access_log off;
+            log_not_found off;
+            root /usr/local/ispconfig/interface/acme/;
+            autoindex off;
+            index index.html;
+            try_files $uri $uri/ =404;
+        }
+
         location / {
             proxy_pass <tmpl_var name='rewrite_target'>;
             <tmpl_if name='rewrite_subdir'>rewrite ^/<tmpl_var name='rewrite_subdir'>(.*) /$1;</tmpl_if>