fix for transferring ownership of groupfolders

Signed-off-by: Vanessa Pertsch <vanessa.pertsch@nextcloud.com>

apps/files/lib/Controller/TransferOwnershipController.php

@@ -97,7 +97,7 @@ public function transfer(string $recipient, string $path): DataResponse {
 			return new DataResponse([], Http::STATUS_BAD_REQUEST);
 		}
 
-		if ($node->getOwner()->getUID() !== $this->userId) {
+		if ($node->getOwner()->getUID() !== $this->userId || !$node->getStorage()->instanceOfStorage(IHomeStorage::class)) {
 			return new DataResponse([], Http::STATUS_FORBIDDEN);
 		}