message: don't ask for witness before witness
diff: #include <memory>
  #include <typeinfo>
  -//#include <checkpointsync.h>
  +#include <kernel.h>
  #if defined(NDEBUG)
  # error "Peercoin cannot be compiled without assertions."
  @@ -4224,7 +4224,7 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
  NodeId staller = -1;
  FindNextBlocksToDownload(pto->GetId(), MAX_BLOCKS_IN_TRANSIT_PER_PEER - state.nBlocksInFlight, vToDownload, staller, consensusParams);
  for (const CBlockIndex *pindex : vToDownload) {
  - uint32_t nFetchFlags = GetFetchFlags(pto);
  + uint32_t nFetchFlags = IsBTC16BIPsEnabled(pindex->nTime) ? GetFetchFlags(pto) : false;
  vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()));
  MarkBlockAsInFlight(m_mempool, pto->GetId(), pindex->GetBlockHash(), pindex);
  LogPrint(BCLog::NET, "Requesting block %s (%d) peer=%d\n", pindex->GetBlockHash().ToString(),
  