Fix check for crontab
Fix check for crontab

The following commands edit keystone's cron table, so check keystone's
and not root's cron table first.

Change-Id: Ib2966d4358a2cb697e8c124c910712aabd024c11
Backport: icehouse
Closes-Bug: #1322342

AlekhyaMallina-Vedams/openstack-manuals,gongysh2004/openstack-manual,openstack/openstack-manuals,saeki-masaki/openstack-manuals,saeki-masaki/openstack-manuals,openstack/openstack-manuals,kairoaraujo/openstack-manuals,openstack/openstack-manuals,kairoaraujo/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,potsmaster/openstack-manuals,potsmaster/openstack-manuals,Akasurde/openstack-manuals,gongysh2004/openstack-manual,openstack/openstack-manuals,Akasurde/openstack-manuals