koji_hub: koji_directory_cleanup: set a valid hour for cleaning up koschei rpms
    
    I am not sure how this worked on rhel7 at all, but on fedora32, cron
    says: (CRON) bad hour (/etc/cron.d/koji-directory-cleanup)
    and I think it just doesn't process the entire file.
    
    Move this to an hour after the log cleanup.
    
    Signed-off-by: Kevin Fenzi <kevin@scrye.com>