react 的升级版 next.js 上使用 element-ui 报错

### Description

引入模块的时候就开始报错：
`ReferenceError: window is not defined
at D:\project\dapp\dpark-react\node_modules\element-react\dist\npm\es5\libs\utils\popper.js:57:16
at root (D:\project\dapp\dpark-react\node_modules\element-react\dist\npm\es5\libs\utils\popper.js:48:26)
at Object. (D:\project\dapp\dpark-react\node_modules\element-react\dist\npm\es5\libs\utils\popper.js:53:3)
at Module._compile (module.js:635:30)
at Object.Module._extensions..js (module.js:646:10)
at Module.load (module.js:554:32)
at tryModuleLoad (module.js:497:12)
at Function.Module._load (module.js:489:3)
at Module.require (module.js:579:17)
at require (internal/module.js:11:18)
at Object. (D:\project\dapp\dpark-react\node_modules\element-react\dist\npm\es5\libs\utils\popper-mixins.js:18:15)
at Module._compile (module.js:635:30)
at Object.Module._extensions..js (module.js:646:10)
at Module.load (module.js:554:32)
at tryModuleLoad (module.js:497:12)
at Function.Module._load (module.js:489:3)`

### Reproduce Steps

1. [First Step]
2. [Second Step]
3. [and so on...]

### Error Trace (if possible)

It's better to post up the error stack for us to trace this issue.

### Solution

What needs to be done to address this issue? Ideally, provide a pull request with a fix.

### Additional Information

Any additional information, configuration or data that might be necessary to reproduce the issue.