fix title in tag page

common/modules/blog/controllers/PostController.php

@@ -52,6 +52,8 @@ class PostController extends BaseController
             throw new NotFoundHttpException('The requested page does not exist.');
         }
 
+        $this->meta_title = Yii::t('app', 'Tag') . ': ' . $model->name . ' - ' . \Yii::$app->params['name'];
+
         return $this->render('tag', [
             'model' => $model,
         ]);