Write the message into the transaction log.

    Args:
      grr_message: A GrrMessage instance.

def Write(self, grr_message):
    """Write the message into the transaction log.

    Args:
      grr_message: A GrrMessage instance.
    """
    grr_message = grr_message.SerializeToString()
    try:
      winreg.SetValueEx(_GetServiceKey(), "Transaction", 0, winreg.REG_BINARY,
                        grr_message)
      self._synced = False
    except OSError:
      pass