Remove @todo comment that has been implemented

src/Controllers/AdminController.php

@@ -26,9 +26,6 @@ class AdminController extends Controller
 		return ! Session::get('orig_user');
 	}
 
-	/**
-	 * @todo Change the background color (or something) so we know we are switched
-	 */
 	public function user_switch_start($id)
 	{
 		if ($this->switch_session() AND $this->switch_authorised($id))