Removed unused import

Author: GrahamCampbell

lib/Gitlab/HttpClient/Plugin/History.php

@@ -3,7 +3,6 @@
 namespace Gitlab\HttpClient\Plugin;
 
 use Http\Client\Common\Plugin\Journal;
-use Http\Client\Exception;
 use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;