message: Bugfix: ensure consistency of m_failed_blocks after reconsiderblock
  Github-Pull:
  Rebased-From:
diff: @@ -2764,6 +2764,7 @@ bool CChainState::ResetBlockFailureFlags(CBlockIndex *pindex) {
  if (pindex->nStatus & BLOCK_FAILED_MASK) {
  pindex->nStatus &= ~BLOCK_FAILED_MASK;
  setDirtyBlockIndex.insert(pindex);
  + g_failed_blocks.erase(pindex);
  }
  pindex = pindex->pprev;
  }
  