DWS/Rabbit interactions failed causes job to get indefinitely stuck in dws-epilog

[grondo]

On elcap we had a job stuck in the dws-epilog after a "DWS/Rabbit interactions failed" exception.

[Oct23 07:34] finish status=0
[  +0.007790] epilog-start description="job-manager.epilog"
[  +0.007843] epilog-start description="dws-epilog"
[  +0.144160] release ranks="all" final=true
[  +2.011065] epilog-finish description="job-manager.epilog" status=0
[Oct23 07:39] exception type="exception" severity=0 note="DWS/Rabbit interactions failed" userid=765
[Oct23 08:24] exception type="cancel" severity=0 note="" userid=62120
[Oct23 08:50] exception type="cancel" severity=0 note="" userid=62120

The job required manual cleanup by posting the epilog-finish event for dws-epilog. I'm not sure if this was the right approach, but perhaps the dws-epilog should somehow be canceled by the "DWS/Rabbit interactions failed" exception.