Fix PHP notice

Plugin.php

@@ -14,7 +14,7 @@ class Plugin extends Base
  'project' => isset($project) ? $project : null,
  'task' => isset($task) ? $task : null,
  'description' => isset($description) ? $description : null,
- 'title' => $title,
+ 'title' => isset($title) ? $title : null,
  ));
  }
 }