on_error callback stops being called after first reconnection

[jeanbmar]

After a failure, this line will set the WebSocketApp instance in reconnecting mode forever:

https://github.com/websocket-client/websocket-client/blob/master/websocket/_app.py#L613

Indeed, setSock will only be called as reconnecting. As a result any further error will be swallowed here:

https://github.com/websocket-client/websocket-client/blob/master/websocket/_app.py#L582

I don't think we even want to swallow the reconnection-specific errors. Should the condition be completely removed?