fixed event php-doc

framework/yii/base/Event.php

@@ -58,7 +58,7 @@ class Event extends Object
 	 * `afterInsert` event:
 	 *
 	 * ~~~
-	 * Event::on([ActiveRecord::className(), ActiveRecord::EVENT_AFTER_INSERT], function ($event) {
+	 * Event::on(ActiveRecord::className(), ActiveRecord::EVENT_AFTER_INSERT, function ($event) {
 	 *     Yii::trace(get_class($event->sender) . ' is inserted.');
 	 * });
 	 * ~~~