Up until now the JobServer was silently losing jobs and only claiming to be
finished - a workaround for this was to restart the campaign until all jobs
were finished according to the database and the campaign's output.
This change fixes the underlying problem, so a single campaign-run suffices
and does no longer lose any jobs.
Debugging this was awful and took us quite some time...
Change-Id: Ie6c982cc3b2ce11128941f1f13be563bae22565c
9c984b9704