raise error "websocket.protocol has no attribute OPEN" if websocket connection has exception

[hhphome]

Since in code, we just connect websocket without checking connect state, so we only met this error when send_commnd.
But in chromewhip/chrome.py:248:
if self._ws.state != websockets.protocol.OPEN: this would raise error since OPEN is in webscokets.protocol.State.
if self._ws.state != websockets.protocol.State.OPEN: should be right