Namespace the DashboardController

refs #5786

application/controllers/DashboardController.php

@@ -1,6 +1,8 @@
 <?php
 /* Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
 
+namespace Icinga\Controller;
+
 use Icinga\Exception\ProgrammingError;
 use Icinga\Forms\ConfirmRemovalForm;
 use Icinga\Forms\Dashboard\DashletForm;