ws.py: don't visit other rooms with charcoal-hq-only
ws.py: don't visit other rooms with charcoal-hq-only

The functionality in chatexchange_extension.py is partial; need
to also prevent ws.py from setting up connections to various rooms
to really make it use Charcoal only.

Charcoal-SE/SmokeDetector,Charcoal-SE/SmokeDetector