HPCC-12128 - MP connections take too long

Resolve mp connection deadlock when A->B and B->A with lower random number

Signed-off-by: Mark Kelly <mark.kelly@lexisnexis.com>
Serializing SocketEndpointV4A's vs SocketEndpointV4's is going to make old clients incompatible (they'll end up being rejected at connect time, with the error message "MP Connect Thread: invalid number of connection bytes serialized from "

Whilst we normally have most things on the same version, we do have cross (MP) comms between platform version.
So I think need to find another way..