message: doc: improve comments relating to block-relay-only peers
diff: @@ -1512,6 +1512,11 @@ void static ProcessGetData(CNode* pfrom, const CChainParams& chainparams, CConnm
  std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
  std::vector<CInv> vNotFound;
  const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
  +
  + // Note that if we receive a getdata for a MSG_TX or MSG_WITNESS_TX from a
  + // block-relay-only outbound peer, we will stop processing further getdata
  + // messages from this peer (likely resulting in our peer eventually
  + // disconnecting us).
  if (pfrom->m_tx_relay != nullptr) {
  LOCK(cs_main);
  