[bug report] El radio parent container binding click triggers double

### Element UI version
2.13.2

### OS/Browsers version
macOs 10.15.4/版本 83.0.4103.61（正式版本） （64 位）

### Vue version
2.6.11

### Reproduction Link
https://codepen.io/seafronthu/pen/MWKaYbm?editable=true%3Dhttps%3A%2F%2Felement.eleme.cn%2F2.13%2F

### Steps to reproduce
点击el-radio的容器div

### What is Expected?
只会触发一次click事件

### What is actually happening?
触发了两次