message: Replace BOOST_FOREACH and NULL, in SendMessages, with C++11 notation
diff: @@ -7197,7 +7197,7 @@ bool SendMessages(CNode *pto)
  pto->nNextAddrSend = PoissonNextSend(nNow, AVG_ADDRESS_BROADCAST_INTERVAL);
  std::vector<CAddress> vAddr;
  vAddr.reserve(pto->vAddrToSend.size());
  - BOOST_FOREACH (const CAddress &addr, pto->vAddrToSend)
  + for (const CAddress &addr : pto->vAddrToSend)
  {
  if (!pto->addrKnown.contains(addr.GetKey()))
  {
  @@ -7232,7 +7232,7 @@ bool SendMessages(CNode *pto)
  }
  // Start block sync
  - if (pindexBestHeader == NULL)
  + if (pindexBestHeader == nullptr)
  pindexBestHeader = chainActive.Tip();
  // Download if this is a nice peer, or we have no nice peers and this one might do.
  bool fFetch = state.fPreferredDownload || (nPreferredDownload == 0 && !pto->fClient && !pto->fOneShot);
  @@ -7299,7 +7299,7 @@ bool SendMessages(CNode *pto)
  // Try to find first header that our peer doesn't have, and
  // then send all headers past that one. If we come across any
  // headers that aren't on chainActive, give up.
  - BOOST_FOREACH (const uint256 &hash, pto->vBlockHashesToAnnounce)
  + for (const uint256 &hash : pto->vBlockHashesToAnnounce)
  {
  BlockMap::iterator mi = mapBlockIndex.find(hash);
  // BU skip blocks that we don't know about. was: assert(mi != mapBlockIndex.end());
  @@ -7312,7 +7312,7 @@ bool SendMessages(CNode *pto)
  fRevertToInv = true;
  break;
  }
  - if (pBestIndex != NULL && pindex->pprev != pBestIndex)
  + if (pBestIndex != nullptr && pindex->pprev != pBestIndex)
  {
  // This means that the list of blocks to announce don't
  // connect to each other.
  @@ -7361,7 +7361,7 @@ bool SendMessages(CNode *pto)
  // in the past.
  if (!pto->vBlockHashesToAnnounce.empty())
  {
  - BOOST_FOREACH (const uint256 &hashToAnnounce, pto->vBlockHashesToAnnounce)
  + for (const uint256 &hashToAnnounce : pto->vBlockHashesToAnnounce)
  {
  BlockMap::iterator mi = mapBlockIndex.find(hashToAnnounce);
  if (mi != mapBlockIndex.end())
  @@ -7510,7 +7510,7 @@ bool SendMessages(CNode *pto)
  std::vector<CBlockIndex *> vToDownload;
  FindNextBlocksToDownload(pto->GetId(), MAX_BLOCKS_IN_TRANSIT_PER_PEER - state.nBlocksInFlight, vToDownload);
  // LOG(REQ, "IBD AskFor %d blocks from peer=%s\n", vToDownload.size(), pto->GetLogName());
  - BOOST_FOREACH (CBlockIndex *pindex, vToDownload)
  + for (CBlockIndex *pindex : vToDownload)
  {
  CInv inv(MSG_BLOCK, pindex->GetBlockHash());
  if (!AlreadyHave(inv))
  