[Bug Report] After entering a value in the selector remote search box, double-click to enter a value. The input box has no value, and the drop-down option has fuzzy search value

### Element UI version
2.15.7

### OS/Browsers version
windows7/Google Chrome 89.0.4389.90

### Vue version
2.6.14

### Reproduction Link
https://codepen.io/emdyxx/pen/vYWdNzG

### Steps to reproduce
1. Selector remote search box input value
2. Double click the entered value
3. Click the input box

### What is Expected?
Follow the steps and you will feel something wrong

### What is actually happening?
Defective actual behavior