Created Unassigned: ForwardedPortDynamic unhandled exception if client terminates socket [1844]

In my experimenting, it wasn't uncommon for a browser to initiate a connection with the SOCKS proxy hosted by SSH.NET, then abort the connection before the response came back.

This resulted in a SocketException on line 24 of ChannelDirectTcpip.NET35.cs (which calls `this._socket.Send`, complaining that the socket wasn't open.

Wrapping the call to `this.InternalSocketSend(data)` on line 159 of ChannelDirectTcpip.cs in a try/catch (and ignoring SocketExceptions) provided a workaround, but I don't know if there's a better solution.

Thanks!