fix(transport): Avoid exit after bad TLS handshake

[domodwyer]

Prevents the server exiting after a bad TLS handshake / error during
accept(). Instead the connection is dropped and the server continues to
serve new clients.

Previously an error would bubble up from the TLS library (tested with
rustls) and would cause:

	Server::builder()
	.rustls_tls(Identity::from_pem(&cert, &key))
	.clone()
	.serve(config.bind_addr(), AnExampleServer::new(endpoint))
	.await?;

to exit with:

	[src/main.rs:85] &e = Error(
		Server,
		Error(
			Accept,
			Custom {
				kind: InvalidData,
				error: CorruptMessage,
			},
		),
	)

This can be reproduced by dialling to a tonic server's socket and sending junk
until it crashes.

Unfortunately I'm a little unsure how to test this!

[LucioFranco]

Awesome, thank you!

[domodwyer]

Thank you for building out tonic!

gRPC services are a fantastic way to incrementally introduce rust to an organisation, having a reliable crate to do so is critical - thanks for the time you've put into it.

[LucioFranco]

@domodwyer I agree! Let me know if there is anything we can help with :)