[Bug Report] Version 2.11.0, server rendering window is not defined

[OrangeXC]

Element UI version

2.11.0

OS/Browsers version

Chrome 75.0.3770.100

Vue version

2.6.10

Reproduction Link

https://github.com/OrangeXC/n2ex

Steps to reproduce

1.克隆 https://github.com/OrangeXC/n2ex

2.升级 element-ui 至 2.11.0

3.npm run dev

What is Expected?

正确渲染网站，因为 2.10.1 完全正常，可以参考

What is actually happening?

window is not defined

[element-bot]

Translation of this issue:

Element UI version

2.11.0

OS/Browsers version

Chrome 75.0.3770.100

Vue version

2.6.10

Reproduction Link

Https://github.com/OrangeXC/n2ex

Steps to reproduce

1. Cloning https://github.com/OrangeXC/n2ex

2. Upgrade element-ui to 2.11.0

3. NPM run dev

What is Expected?

Render the website correctly, because 2.10.1 is completely normal, you can refer to it.

What is actually happening?

Window is not defined

[iamkun]

fixed in 2.11.1