An informational message for the protocol is useful for sending
messages to a node that is not required to be relayed.
This message is introduced by starting with an ACK message for a set
of references being synced. This fixes an issue for announcing to a
node that is already synced, since it can now ACK that it received the
message and replies that it is synced.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett