How to resolve HTTP/1.1 101 null

[nevatia]

WebSocket server is returning HTTP/1.1 101 null instead of the standard HTTP/1.1 101 Switching Protocols, which is causing picows to reject the handshake. How to resolve this. Any method to avoid this error and resume connection.

[tarasko]

Yes, this is just a one line change here:
https://github.com/tarasko/picows/blob/master/picows/picows.pyx#L1339

I wonder what kind of server returns this?