This commit enables Kilo to ignore changes to the endpoints of peers
that sit behind a NAT gateway. We use the heuristic of a non-zero
persistent keepalive to decide whether the endpoint field should be
ignored. This will allow NATed peers to roam and for every node in the
cluster to have a different value for a peer's endpoint, as is natural
when a peer's connections are NATed.
Signed-off-by: Lucas Servén Marín <lserven@gmail.com>
0d199db009