message: block spam filter, validate non null nodestate
diff: @@ -4818,6 +4818,7 @@ bool ProcessNewBlock(CValidationState& state, CNode* pfrom, CBlock* pblock, CDis
  // Check spamming
  if(pfrom && GetBoolArg("-blockspamfilter", DEFAULT_BLOCK_SPAM_FILTER)) {
  CNodeState *nodestate = State(pfrom->GetId());
  + if(nodestate != nullptr) {
  nodestate->nodeBlocks.onBlockReceived(pindex->nHeight);
  bool nodeStatus = true;
  // UpdateState will return false if the node is attacking us or update the score and return true.
  @@ -4831,6 +4832,7 @@ bool ProcessNewBlock(CValidationState& state, CNode* pfrom, CBlock* pblock, CDis
  if (!nodeStatus)
  return error("%s : AcceptBlock FAILED - block spam protection", __func__);
  }
  + }
  return error("%s : AcceptBlock FAILED", __func__);
  }
  }
  