Receiving `KeyError: 3` during ARC Restart

Describe the bug
After the error received in #631, I attempted an arcrestart and get the following error

Traceback (most recent call last):
  File "/home/calvin.p/Code/ARC//ARC.py", line 69, in <module>
    main()
  File "/home/calvin.p/Code/ARC//ARC.py", line 65, in main
    arc_object.execute()
  File "/home/calvin.p/Code/ARC/arc/main.py", line 583, in execute
    fine_only=self.fine_only,
  File "/home/calvin.p/Code/ARC/arc/scheduler.py", line 486, in __init__
    self.schedule_jobs()
  File "/home/calvin.p/Code/ARC/arc/scheduler.py", line 502, in schedule_jobs
    self.run_conformer_jobs()
  File "/home/calvin.p/Code/ARC/arc/scheduler.py", line 1050, in run_conformer_jobs
    self.process_conformers(label)
  File "/home/calvin.p/Code/ARC/arc/scheduler.py", line 1752, in process_conformers
    conformer=i,
  File "/home/calvin.p/Code/ARC/arc/scheduler.py", line 833, in run_job
    self.save_restart_dict()
  File "/home/calvin.p/Code/ARC/arc/scheduler.py", line 3472, in save_restart_dict
    + [self.job_dict[spc.label]['tsg'][get_i_from_job_name(job_name)].as_dict()
  File "/home/calvin.p/Code/ARC/arc/scheduler.py", line 3471, in <listcomp>
    for job_name in self.running_jobs[spc.label] if 'conformer' in job_name] \
KeyError: 3

Attached is the restart file.

restart.zip

Start by reproducing arcrestart with the attached restart.zip, then inspect arc/scheduler.py around save_restart_dict(), run_job(), and process_conformers() using the traceback. Confirm why the conformer lookup reaches a missing key and verify that restarting no longer raises KeyError: 3.