Trigger onDisconnect callback on wslay errors

[redbaron]

disconnect's remote argument actually means "transport initiated" when true and "client initiated" when false. wslay error causes disconnect from the transport side (even though remote side didn't sent us close frame), therefore should be calling this->disconnect(true)

[lugehorsam]

I'm not sure I understand, here's the comment for remote in the disconnect info:

        /// true if close was initiated by server.
        bool remote = false;

[redbaron]

comment is inaccurate. it was true at the time when wslay IO errors were not processed , so only reason of transport initiated disconnect was if remote server closes connection. Now that IO errors also cause disconnect, more appropriate name for this variable will be transport_initiated or something like this.

We want to call onDisconnect when transport initiates disconnect and we don't want to call it (from transport level), when RtClient initiates disconnect, because higher level RtClient does it already.

[lugehorsam]

We don't use the remote field, do we? It's only intended for external users as far as I know. I think we should keep remote and add transport_initiated instead although I'm not sure in what situations that would be useful for them to know.

[redbaron]

We do use it: https://github.com/heroiclabs/nakama-cpp/blob/master/impl/wsWslay/NWebsocketWslay.cpp#L309

• more uses introduced in this very PR

[lugehorsam]

We don't read the value.

[redbaron]

If remote is true we fire disconnect callback: https://github.com/heroiclabs/nakama-cpp/blob/master/impl/wsWslay/NWebsocketWslay.cpp#L243