Re: Allowing custom payload and client warnings for auth messages

[Abe Ratnofsky]

I don’t think there’s any ambiguity in the spec for empty response types, they 
should still respect header flags: 
https://github.com/apache/cassandra/blob/4a548b0f289a94ce466011dba2579dcaafdba4b9/doc/native_protocol_v5.spec#L446