Early exit of cleanup -> bad supervisorctl status

[rynge]

docker-software-base/container_cleanup.sh

Lines 3 to 5 in c6a2f3f

	if [[ -z $(shopt -s nullglob && echo /etc/osg/image-cleanup.d/*.sh) ]]; then
	exit 0
	fi

This early exits make supervisorctl status complain:

# supervisorctl status; echo exited $?
condor_master                    RUNNING   pid 104, uptime 0:01:43
container_cleanup                EXITED    Sep 16 01:35 AM
crond                            RUNNING   pid 105, uptime 0:01:43
prometheus                       RUNNING   pid 193, uptime 0:01:22
exited 3

I use supervisorctl status in some health checks, so my preference would be to keep the previous sleep forever approach and a clean supervisorctl status. However, I could be convinced to change the health checks if there are other benefits to exit early.