[Bug Report] el-select >In some cases, modifying its disable attribute changes the height style

[Finyu]

Element UI version

2.8.2

OS/Browsers version

window7/Chrome

Vue version

2.6.10

Reproduction Link

https://codepen.io/anon/pen/PvxQKw?&editable=true

Steps to reproduce

Add the parent node p to the select component, give it the lineHeight attribute of 50px, and then modify the disable attribute of the select,

What is Expected?

Select height unchanged

What is actually happening?

you will find that the height of the select has changed to 50px,

[noxxxxxxxx]

Element UI version

2.8.2

OS/Browsers version

window7/Chrome

Vue version

2.6.10

Reproduction Link

https://codepen.io/hjoker/pen/PrqRvp

use size="small" and :disabled="test === 1" in select component , if variable test value change in the Promise or setTimeout function, size="small" will be useless.

[ziyoung]

fixed in #15989