Fixes #6995: restore pulp_celerybeat to list of services to restart.

[waldenraines]

The service pulp_celerybeat was removed from the list of services
restarted with a katello:reset during the pulp 2.4 upgrade. Restarting
the service is working fine now so this commit restores pulp_celerybeat
to the list of services to start/stop during katello:reset.

http://projects.theforeman.org/issues/6995

[ehelms]

@waldenraines what does "working fine" mean in this context mean? Is there a test scenario for this or a pulp developer who can thumbs up it?

[waldenraines]

"Working fine" as in restarting it is no longer a problem.

This first came about because I was speaking with @jlsherrill about pulp_celerybeat being stopped after a katello reset. He said we used to restart it during a katello reset but had to remove that during the 2.4 migration. I reset several times with this in place and everything worked as expected. I'm not sure how I got into the state of pulp_celerybeat not running but I am not the only one who has been in that state.

[jlsherrill]

@ehelms yeah, i chatted with bmbouter and we did remove it from that list previously the issues that required that are now resolved. So we should add it back in case you update pulp and run a katello:reset. The fact that it is dying he does thing is a bug and we're investigating.

[jlsherrill]

ACK