job manager running job count is incorrect

[grondo]

During a full system shutdown, after all running jobs were canceled, the job manager still thought 3 jobs were running:

grondo@elcap1:~$ flux jobs -Af running
       JOBID USER     NAME       ST NTASKS NNODES     TIME INFO
grondo@elcap1:~$ flux queue status -v | grep running
3 running jobs

This prevented shutdown by causing flux queue idle to hang. The program had to be manually killed to allow shutdown to proceed.

Problem: There isn't much ability to debug this situation. We may need to add some way to inspect which jobs Flux thinks are still running or some other clever way to get more debug if this occurs again.