Fixed websocket support in `hs.httpserver:start()`

[latenitefilms]

• Closes #3468

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 27.70%. Comparing base (ec9a8ea) to head (45eaf01). Report is 16 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #3665 +/- ## ========================================== + Coverage 27.65% 27.70% +0.04% ========================================== Files 191 191 Lines 43472 43528 +56 ========================================== + Hits 12023 12059 +36 - Misses 31449 31469 +20 ```