Kennedy is not sending close_notify

[dimkr]

Hello!

My client distinguishes between close_notify (as the Gemini spec requires) and a FIN: it warns the user when it doesn't know whether or not the page is truncated. Only few capsules (mostly old ones, before this requirement) don't send close_notify so it's mostly OK. Kennedy is also affected (😢) and that's the only reason why I don't bookmark it in the default configuration file of my client.

If I understand correctly, SslStream.ShutdownAsync() does this by calling SSL_shutdown(). However, the SslStream.Dispose() call of the using block in ProcessRequest() closes the connection without calling ShutdownAsync() first.