build(deps-dev): Bump webpack from 4.42.0 to 4.42.1 in /addon (#476)

Bumps [webpack](https://github.com/webpack/webpack) from 4.42.0 to 4.42.1.
- [Release notes](https://github.com/webpack/webpack/releases)
- [Commits](webpack/webpack@v4.42.0...v4.42.1)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

addon/package-lock.json

@@ -12,7 +12,7 @@
     "eslint-plugin-mozilla": "^0.9.0",
     "eslint-plugin-no-unsanitized": "^3.0.2",
     "web-ext": "^4.1.0",
-    "webpack": "^4.42.0",
+    "webpack": "^4.42.1",
     "webpack-cli": "^3.3.11"
   },
   "scripts": {