nginx: Add rule to pass through acme-challenge

nginx/http.template

@@ -12,4 +12,9 @@ server {
         proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
         proxy_set_header  X-Forwarded-Proto http;
     }
+
+    location ^~ /.well-known/acme-challenge {
+        allow all;
+        alias /var/www/html/.well-known/acme-challenge;
+    }
 }