Minor fix in paxos.conf. Option learner-catchup -> learner-catch-up.
Minor fix in paxos.conf. Option learner-catchup -> learner-catch-up.

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