update data does not update the tree view

### question
when the 'treeData' was changed,but the tree has not change and it's just display blank。

### expected

the 'treeData' change,the view change.

```
<DraggableTree
      class="catalog-tree"
      :data="treeData"
      crossTree
      :draggable="false"
      ref="draggabletree"
    >
...
</DraggableTree>
```
