message: Move incrementing the messageNonce to the end of function execution
diff: @@ -98,11 +98,12 @@ contract OVM_L2CrossDomainMessenger is
  messageNonce
  );
  - messageNonce += 1;
  sentMessages[keccak256(xDomainCalldata)] = true;
  _sendXDomainMessage(xDomainCalldata, _gasLimit);
  emit SentMessage(_target, msg.sender, _message, messageNonce, _gasLimit);
  +
  + messageNonce += 1;
  }
  /**
  