message: Don't send 'sendaddrv2' to pre-70016 software
diff: @@ -2375,7 +2375,13 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat
  m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::VERACK));
  // Signal ADDRv2 support (BIP155).
  + if (greatest_common_version >= 70016) {
  + // BIP155 defines addrv2 and sendaddrv2 for all protocol versions, but some
  + // implementations reject messages they don't know. As a courtesy, don't send
  + // it to nodes with a version before 70016, as no software is known to support
  + // BIP155 that doesn't announce at least that protocol version number.
  m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::SENDADDRV2));
  + }
  pfrom.nServices = nServices;
  pfrom.SetAddrLocal(addrMe);
  