fix: Cannot read property 'pop' of undefined

webpack-contrib/mini-css-extract-plugin#257
[UTCORE-121]

Author: Kalin Krustev

preset.js

@@ -154,6 +154,7 @@ module.exports = ({
                         ...prev,
                         [chunk]: {
                             test: RegExp(`[\\\\/]node_modules[\\\\/]${chunk}`),
+                            enforce: true,
                             name: chunk,
                             chunks: 'all'
                         }