fix: prevent duplicate warning for missing websocketTopicAuth in ConfigValidator

AdminForth/1859/need-to-show-this-warning-only

Author: yaroslav8765

adminforth/modules/configValidator.ts

@@ -1218,8 +1218,12 @@ export default class ConfigValidator implements IConfigValidator {
       }
 
       if (!newConfig.auth.websocketTopicAuth) {
+        let websocketTopicAuthWarned = false;
         newConfig.auth.websocketTopicAuth = async (topic: string, adminUser: AdminUser) => {
-          afLogger.warn('websocketTopicAuth is not provided. Public access to websocket topics (except /opentopic) is blocked.');
+          if (!websocketTopicAuthWarned) {
+            websocketTopicAuthWarned = true;
+            afLogger.warn('websocketTopicAuth is not provided. Public access to websocket topics (except /opentopic) is blocked.');
+          }
           if (!adminUser) {
             // don't allow anonymous users to subscribe
             return false;