Bump webpack-dev-server from 3.1.10 to 3.1.11 in /webpack4

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 3.1.10 to 3.1.11.
- [Release notes](https://github.com/webpack/webpack-dev-server/releases)
- [Changelog](https://github.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md)
- [Commits](webpack/webpack-dev-server@v3.1.10...v3.1.11)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

webpack4/package.json

@@ -9,6 +9,6 @@
     "html-webpack-plugin": "^3.2.0",
     "ts-loader": "^5.3.0",
     "webpack": "^4.25.1",
-    "webpack-dev-server": "^3.1.10"
+    "webpack-dev-server": "^3.1.11"
   }
 }