[Bug Report] 【el-collapse-transition】will fail under the higher version of vue

### Element UI version
2.9.0

### OS/Browsers version
chrome

### Vue version
2.6.12

### Reproduction Link
https://github.com/ElemeFE/element/blob/dev/src/transitions/collapse-transition.js

### Steps to reproduce
```js
import CollapseTransition from 'element-ui/src/transitions/collapse-transition';
import Vue from 'vue'

Vue.component(CollapseTransition.name, CollapseTransition)
```

The higher version of vue modified the internal implementation, which caused el-collaplse-transition to fail

### What is Expected?
will work

### What is actually happening?
fail