Bump css-loader from 3.3.2 to 3.4.0

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 3.3.2 to 3.4.0.
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](webpack/css-loader@v3.3.2...v3.4.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package-lock.json

@@ -87,7 +87,7 @@
     "babel-eslint": "^10.0.3",
     "babel-loader": "^8.0.6",
     "babel-plugin-transform-es2015-arrow-functions": "^6.22.0",
-    "css-loader": "^3.3.2",
+    "css-loader": "^3.4.0",
     "eslint": "^5.16.0",
     "eslint-config-nextcloud": "0.1.0",
     "eslint-config-standard": "^12.0.0",