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>
The connectsect block at the top of attachSocket prevents it from running through while in connect().  But we need one of the attachSocket()s to proceed to end the deadlock with another process and achieve this by stopping one of the connect()s, so that it releases connectsect.  Hence the exchange of some new info between attachSocket() and connect() threads, protected by new attachsect CS.