[Bug Report] When set a attribute "destory-on-close='true'" on a el-dialog which has a child el-tabs component will cause the browser crash

### Element UI version
2.15.0

### OS/Browsers version
Windows 10 Enterprise 1909 / Chrome Version 90.0.4430.93 (Official Build) (64-bit)

### Vue version
2.6.12

### Reproduction Link
https://codepen.io/ilexwg/pen/mdRgLZV

### Steps to reproduce
- The el-dialog has a child component el-tabs
- Set the destroy-on-close true on the el-dialog
- If you want to close the el-dialog, the browser will crash

P.S. Some clues:
If you don't set destroy-on-close true on the el-dialog, everything is ok.
If you don't use el-tabs in the el-dialog, everything is ok.
I think the problem is using , el-tabs at the same time.

I have a very headache about this bug! :(

### What is Expected?
I can use el-dialog with attribute :destroy-on-close="true" and a child el-tabs component, and can close el-dialog.

### What is actually happening?
When I use el-dialog with attribute :destroy-on-close="true" and a child el-tabs component, I can not close el-dialog which makes browser crash!