Merge pull request #63922 from nextcloud/backport/60147/stable34

[stable34] fix(files_external): set size to -1 for root entry

Author: AndyScherzinger

apps/files_external/lib/Service/MountCacheService.php

@@ -119,7 +119,7 @@ private function getCacheEntryForRoot(IUser $user, StorageConfig $storage): ICac
 		$data = [
 			'path' => '',
 			'path_hash' => md5(''),
-			'size' => 0,
+			'size' => -1,
 			'unencrypted_size' => 0,
 			'mtime' => 0,
 			'mimetype' => ICacheEntry::DIRECTORY_MIMETYPE,