[Bug Report] Select selector clearable state if the value is set to empty clearance and the corresponding label is not displayed, this problem occurs in version 2.82

[sntpPro]

Element UI version

2.8.2

OS/Browsers version

win10 chrome 73.0.3683.86

Vue version

2.6.10

Reproduction Link

https://codepen.io/webxiaoz/pen/yrwRmw

Steps to reproduce

在选择除全部以外选项再清除后，不会回到value为空的label选项，在2.63版本上是正常的，从更新到2.82版本就出现此问题

What is Expected?

恢复到2.63版本的那种效果

What is actually happening?

希望解决

[element-bot]

Translation of this issue:

Element UI version

2.8.2

OS/Browsers version

Win10 chrome 73.0.3683.86

Vue version

2.6.10

Reproduction Link

Https://codepen.io/webxiaoz/pen/yrwRmw

Steps to reproduce

After choosing all but one option and clearing it, the label option with empty value is not returned. It is normal in version 2.63. This problem occurred from update to version 2.82.

What is Expected?

Restore to version 2.63

What is actually happening?

Hope to solve

[sntpPro]

并未解决