rename task to project task, task_user to project_task_user, fix behavior

backend/modules/task/views/task-user/update.php

@@ -2,7 +2,7 @@
 
 
 /* @var $this yii\web\View */
-/* @var $model backend\modules\task\models\TaskUser */
+/* @var $model backend\modules\task\models\ProjectTaskUser */
 /* @var $task_id  */
 
 $this->title = 'Изменить назначение';