Remove duplicate folder update event listener in renderer.js

renderer.js

@@ -598,8 +598,4 @@ folders.forEach(folderObj => {
     }
   });
 
-  window.electronAPI.onFolderUpdated(folderObj => {
-    // Render Sidebar neu, um den Monitoring-Button sofort zu aktualisieren
-    renderSidebar();
-  });
 });