[Bug Report] The height of <el-input type='textarea' autosize /> is abnormal on IE11!

### Element UI version
2.13.0

### OS/Browsers version
IE11

### Vue version
2.6.11

### Reproduction Link
https://codepen.io/lky5230/pen/MWYvVXR

### Steps to reproduce
1、Copy and reproduce the link code to the local HTML file
2、Open the HTML with ie11 browser

### What is Expected?
Highly normal

### What is actually happening?
The height is abnormal, even two to three times higher