Unneded "use" removed

mod/ping.php

@@ -24,7 +24,6 @@ use Friendica\Content\ForumManager;
 use Friendica\Content\Text\BBCode;
 use Friendica\Core\Cache\Duration;
 use Friendica\Core\Hook;
-use Friendica\Core\Logger;
 use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Model\Contact;