Fixes init of current job in snapshot worker

Setting current_job in '_process_job' method leaves it
uninitialized over an error path when fetching the schedule fails.
This results in a TypeError when '_get_updated_job_timeout' tries
to access the job when invoked by '_get_updated_job_timeout()'

Also, fixes another issue with passing incorrect argument to
'_job_processing' method.
Merge pull request #331 from hmakkapati/rm8556

Fixes init of current job in snapshot worker