[Bug Report] a bug with "SELECT" component - need to click twice to chose a option on safari with iOS13

### Element UI version
2.12.0

### OS/Browsers version
safari 13 on iOS13

### Vue version
2.6.10

### Reproduction Link
https://jsfiddle.net/mmx38qxw/

### Steps to reproduce
(1) open the page with on safari 13 with iOS 13,
(2) click the SELECT component and try to chose an option, but it need to click twice and then it can chose the option.

### What is Expected?
it should just click once to chose the option.

### What is actually happening?
click the SELECT component and try to chose an option, but it need to click twice and then it can chose the option.