fix(package): update extract-css-chunks-webpack-plugin to version 4.7.1

Closes #131

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
   ],
   "dependencies": {
     "@nuxt/friendly-errors-webpack-plugin": "^2.4.0",
-    "extract-css-chunks-webpack-plugin": "^3.3.2",
+    "extract-css-chunks-webpack-plugin": "^4.7.1",
     "js-yaml": "^3.10.0",
     "style-loader": "^0.23.0"
   },