Bump engine.io from 4.0.4 to 4.1.2 in /examples/server/javascript (#267)

Bumps [engine.io](https://github.com/socketio/engine.io) from 4.0.4 to 4.1.2.
- [Release notes](https://github.com/socketio/engine.io/releases)
- [Changelog](https://github.com/socketio/engine.io/blob/4.1.2/CHANGELOG.md)
- [Commits](socketio/engine.io@4.0.4...4.1.2)

---
updated-dependencies:
- dependency-name: engine.io
  dependency-type: direct:production
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

examples/server/javascript/package-lock.json

@@ -3,7 +3,7 @@
   "version": "0.1.0",
   "dependencies": {
     "enchilada": "0.13.0",
-    "engine.io": "^4.0.0",
+    "engine.io": "^4.1.2",
     "engine.io-client": "^4.0.0",
     "express": "^4.17.1",
     "smoothie": "1.19.0"