Fixes duplicate delivery in case of concurrent proposers.
Fixes duplicate delivery in case of concurrent proposers.

tyh20082000/libpaxos,tudang/paxosudp,tudang/paxosudp,tudang/paxosudp,tyh20082000/libpaxos,tudang/paxosudp,tyh20082000/libpaxos,tudang/paxosudp,tudang/paxosudp,tyh20082000/libpaxos