message: Fix wrong diff retarget block for hardfork
diff: @@ -2379,7 +2379,7 @@ unsigned int static GetNextWorkRequired(const CBlockIndex* pindexLast, const CBl
  }
  // 02/11/2017 - Increase diff to match with new hashrates of Lyra2Z algo
  - if ((!fTestNet && pindexLast->nHeight + 1 == 20502) || (fTestNet && pindexLast->nHeight + 1 == 102) ) {
  + if ((!fTestNet && pindexLast->nHeight + 1 == 20500) || (fTestNet && pindexLast->nHeight + 1 == 100) ) {
  CBigNum bnNew = CBigNum().SetCompact((pindexLast->nBits)*15000);
  printf("Lyra2Z HARDFORK - Before: %08x %s\n", pindexLast->nBits, CBigNum().SetCompact(pindexLast->nBits).getuint256().ToString().c_str());
  printf("Lyra2Z HARDFORK - After: %08x %s\n", bnNew.GetCompact(), bnNew.getuint256().ToString().c_str());
  