修复未选中图片情况下，预览图界面点击完成会添加当前图数据作为选中图，但是界面UI不更新的bug

TZImagePickerController/TZImagePickerController/TZPhotoPreviewController.m

@@ -383,8 +383,7 @@
     
     // 如果没有选中过照片 点击确定时选中当前预览的照片
     if (_tzImagePickerVc.selectedModels.count == 0 && _tzImagePickerVc.minImagesCount <= 0) {
-        TZAssetModel *model = _models[self.currentIndex];
-        [_tzImagePickerVc addSelectedModel:model];
+        [self select:_selectButton];
     }
     NSIndexPath *indexPath = [NSIndexPath indexPathForItem:self.currentIndex inSection:0];
     TZPhotoPreviewCell *cell = (TZPhotoPreviewCell *)[_collectionView cellForItemAtIndexPath:indexPath];