message: fix(shell_automaton): don't graylist when nack received with
  AlreadyConnected motive
diff: @@ -528,7 +528,15 @@ where
  };
  }
  // TODO: use potential peers in nack message.
  - AckMessage::Nack(_) => {}
  + AckMessage::Nack(info) => match info.motive() {
  + NackMotive::AlreadyConnected => {
  + store.dispatch(PeerDisconnectAction {
  + address: action.address,
  + });
  + return;
  + }
  + _ => {}
  + },
  AckMessage::NackV0 => {}
  }
  // peer nacked us so we should graylist him.
  