Forgotten "use"

src/Core/UserImport.php

@@ -7,6 +7,7 @@ namespace Friendica\Core;
 use Friendica\App;
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
+use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\Photo;
 use Friendica\Object\Image;