Fix streaming websocket handshake with `Sec-WebSocket-Protocol`
refs !1381 (merged)
Currently, when trying to connect to streaming with the Sec-WebSocket-Proctocol
header, handshake fails because response hasn't Sec-WebSocket-Proctocol
header.
failed: Error during WebSocket handshake: Sent non-empty 'Sec-WebSocket-Protocol' header but no response was received