Prevent reading key on SFTP stat bool

Signed-off-by: John Molakvoæ <skjnldsv@protonmail.com>

Author: skjnldsv

apps/files_external/lib/Lib/Storage/SFTP.php

@@ -327,6 +327,9 @@ public function opendir($path) {
 	public function filetype($path) {
 		try {
 			$stat = $this->getConnection()->stat($this->absPath($path));
+			if (!is_array($stat) || !array_key_exists('type', $stat)) {
+				return false;
+			}
 			if ((int) $stat['type'] === NET_SFTP_TYPE_REGULAR) {
 				return 'file';
 			}