Invalid transport websocket error

[globalistas]

On my instance I started getting the occasional Invalid transport websocket errors, accompanied with Nginx 499 errors. This manifests itself by websockets basically crashing - chat clears out and voting not registering for others on sockets. Corrects itself after a while, then comes back.

@Polsaker mentioned this might warrant updating the project to suppor python-engineio v4 (along with upgrading pyton-socketio and flaskio).