fixed: do not try to add menu item on non saved entities

Author: jdalsem

classes/ColdTrick/DatarootBrowser/Menus/EntityMenu.php

@@ -25,7 +25,7 @@ public static function register(\Elgg\Event $event): ?MenuItems {
 		}
 
 		$entity = $event->getEntityParam();
-		if (!$entity instanceof \ElggEntity) {
+		if (!$entity instanceof \ElggEntity || empty($entity->guid)) {
 			return null;
 		}