[Bug Report] el-select with multiple and filterable property can not be closed by clicking the input area

### Element UI version
2.12.0

### OS/Browsers version
75.0.3770.100

### Vue version
2.6.10

### Reproduction Link
https://codepen.io/AnnushkaSh/pen/aggoPE

### Steps to reproduce
Create **multiple and filterable** el-select.
Click on select component and then click on the input area.

### What is Expected?
el-select-dropdown component will be closed

### What is actually happening?
el-select-dropdown component is not closing

It's dublicate #16559 and fixed in current version (2.12), but be reproduced again :-( .