message: Add replay protection for V3
diff: @@ -98,7 +98,7 @@ public:
  bool IsForkV2(int64_t nTime) const { return nTime > nForkV2Time; }
  bool IsForkV3(int64_t nTime) const { return nTime > nForkV3Time; }
  - int GetForkId(int64_t nTime) const { return (nTime > nForkV2Time) ? 2 : 0; }
  + int GetForkId(int64_t nTime) const { return (nTime > nForkV3Time) ? 3 : (nTime > nForkV2Time) ? 2 : 0; }
  const CBigNum BnProofOfWorkLimit() const { return bnProofOfWorkLimit; }
  const CBigNum BnProofOfStakeLimit() const { return bnProofOfStakeLimit; }
  