fix if translation enabled on Model to add a \ for Yii

Class 'common\modules\mediating\models\Yii' not found
    * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
            'id'            => Yii::t('app', 'ID'),
            'gallery_id'    => Yii::t('app', 'Gallery ID'),
            'image_id'      => Yii::t('app', 'Image ID'),
            'sort_order'    => Yii::t('app', 'Sort Order'),
            'favorit'       => Yii::t('app', 'Favorit'),
            'favorit_order' => Yii::t('app', 'Favorit Order'),
2. yii\base\Application::handleFatalError()