This commit also changes the default sendcmpct version in the functional
test to `2`, since this is the version that nodes expect, prior to this
commit, nowhere in the functional test framework was the default version
value used:
git grep -P 'msg_sendcmpct\((?![^)]*version\s*=)' HEAD^
`version=2` is a sensible default, since this is the version nodes
currently expect in the SENDCMPCT handshake.
9c5dd2926a