Inconsistent Reason tag on failed job task sessions in API

[pwinkeler]

With some unfortunate regularity our CIFS mounted target repository drops traffic and the VM at hand fails to back up. When it does so, the Veeam console tells us that a network connection was dropped. So far so good (in a way). Now with the API, the Reason field for those same failed job task sessions simply lists the description of the failed disk. That is not helpful when trying to diagnose what is going on. Please fix to list the same description that the console gives.