fix subprotocol for granian

[adhami3310]

No description provided.

[masenf]

still doesn't work for uvicorn in dev mode accessing on chrome

[gi0baro]

FYI, the ASGI protocol specifies you should just use the subprotocol message field, and avoid to have sec-websocket-protocol in headers. ref: https://asgi.readthedocs.io/en/latest/specs/www.html#accept-send-event

[adhami3310]

FYI, the ASGI protocol specifies you should just use the subprotocol message field

Thanks for the link, we were struggling with this a bit. The issue is that Granian/Uviocorn/Gunicorn behave slightly differently in different systems. We couldn't figure out why and how to reproduce it reliably so we opted out for using the header if it's there and subprotocol if it's there.