Bump webpack-dev-server

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 2.4.2 to 3.9.0.
- [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@v2.4.2...v3.9.0)

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

Author: dependabot[bot]

src/AbpCompanyName.AbpProjectName.Web/wwwroot/lib/sweetalert/package.json

@@ -71,7 +71,7 @@
     "vinyl-source-stream": "^1.1.0",
     "webpack": "3.5.5",
     "webpack-bundle-analyzer": "3.6.0",
-    "webpack-dev-server": "2.4.2",
+    "webpack-dev-server": "3.9.0",
     "webpack-merge": "4.1.0",
     "whatwg-fetch": "^2.0.3"
   },