Previously the FG1000 and MFD assumed that all notifications received
via Emesary had a Device_Id field. This is true for
notifications.PFDEventNotification.DefaultType but not for other
messages - e.g. those generated by the AN SPN 46 system on the
carrier.
The effect of this was that when Nimitz was loaded, the FG1000 stopped
working with various errors.
This fix checks the notification type before the Device_Id.
76cfa2c077