substr storage id to prevent problems with storing the change id in appconfig

apps/files_external/lib/google.php

@@ -55,7 +55,7 @@ class Google extends \OC\Files\Storage\Common {
 			$this->service = new \Google_DriveService($client);
 			$this->root = isset($params['root']) ? $params['root'] : '';
 			$token = json_decode($params['token'], true);
-			$this->id = 'google::'.$params['client_id'].$token['created'];
+			$this->id = 'google::'.substr($params['client_id'], 0, 30).$token['created'];
 		} else {
 			throw new \Exception('Creating \OC\Files\Storage\Google storage failed');
 		}