wireproto: only advertise HTTP-specific capabilities to HTTP peers (BC) Previously, the capabilities list was protocol agnostic and we advertised the same capabilities list to all clients, regardless of transport protocol. A few capabilities are specific to HTTP. I see no good reason why we should advertise them to SSH clients. So this patch limits their advertisement to HTTP clients. This patch is BC, but SSH clients shouldn't be using the removed capabilities so there should be no impact.

protocol: declare transport protocol name We add an attribute to the HTTP and SSH protocol implementations identifying the transport so future patches can conditionally expose capabilities on a per-transport basis.