fix: missing semi-colon

Author: ceelogre

beta_.conf

@@ -13,7 +13,7 @@ server {
         set $backend $HTTP_BACKEND_URL;
 
         if ($http_upgrade = 'websocket') {
-            set $backend $WS_BACKEND_URL
+            set $backend $WS_BACKEND_URL;
         }
         proxy_pass $backend;
         proxy_http_version 1.1;