message: change location of assert to right after pindexprev is first assigned a value
diff: @@ -3647,12 +3647,12 @@ bool AcceptBlockHeader(const CBlockHeader &block,
  block.hashPrevBlock.ToString(), hash.ToString()),
  0, "bad-prevblk");
  pindexPrev = (*mi).second;
  + assert(pindexPrev);
  if (pindexPrev->nStatus & BLOCK_FAILED_MASK)
  return state.DoS(100, error("%s: previous block invalid", __func__), REJECT_INVALID, "bad-prevblk");
  // If the parent block belongs to the set of checkpointed blocks but it has a mismatched hash,
  // then we are on the wrong fork so ignore
  - assert(pindexPrev);
  if (fCheckpointsEnabled && !CheckAgainstCheckpoint(pindexPrev->nHeight, *pindexPrev->phashBlock, chainparams))
  return error("%s: CheckAgainstCheckpoint(): %s", __func__, state.GetRejectReason().c_str());
  