message: Make fDisconnect an std::atomic
diff: @@ -347,7 +347,7 @@ public:
  bool fInbound;
  bool fNetworkNode;
  bool fSuccessfullyConnected;
  - bool fDisconnect;
  + std::atomic_bool fDisconnect;
  // We use fRelayTxes for two purposes -
  // a) it allows us to not relay tx invs before receiving the peer's version message
  // b) the peer may tell us in their version message that we should not relay tx invs
  