[Bug Report] [Tabs]Tab Item surrounded by border

[bluejfox]

Element UI version

2.4.0

OS/Browsers version

Google Chrome 66.0.3359.181

Vue version

2.5.16

Reproduction Link

https://jsfiddle.net/phoenixlhan/r0v6uvbn/

Steps to reproduce

1.Click 角色管理 Tab.

2.Click 确定 Button.

What is Expected?

When before-leave function returned a promise and resolve, tab item will not be surrounded by border.

What is actually happening?

When before-leave function returned a promise and resolve, tab item surrounded by border.

[element-bot]

Translation of this issue:

Element UI version
2.4.0

OS/Browsers version
Google Chrome 66.0.3359.181

Vue version
2.5.16

Reproduction Link
https://jsfiddle.net/phoenixlhan/r0v6uvbn/

Steps to reproduce
1.Click role management Tab.

2.Click determines Button.
What is Expected?

When before-leave function returned a promise and resolve, tab item don't item
What is actually happening?

When before-leave function returned a promise and resolve, tab item focus, tab