使用手淘VW适配方案后造成伪类使用content报错的解决办法

报错如下：

warning  in ./src/style/common.scss

Module Warning (from ./node_modules/postcss-loader/src/index.js):
Warning

(410:1) '.is-progress::before' already has a 'content' property, give up to overwrite it.

 @ ./src/style/common.scss 4:14-226 14:3-18:5 15:22-234
 @ ./src/main.js
 @ multi (webpack)-dev-server/client?http://192.168.1.81:8080/sockjs-node (webpack)/hot/dev-server.js ./src/main.js

报错原因：

postcss-viewport-units 插件自动给每个元素添加了content

解决办法：

配置.postcssrc.js的postcss-viewport-units：

'postcss-viewport-units': {
  filterRule: rule => rule.selector.includes('::after') && rule.selector.includes('::before') && rule.selector.includes(':after') && rule.selector.includes(':before')
}