engine: Delete jobs that their steps have no async-tasks
engine: Delete jobs that their steps have no async-tasks

Sometimes async tasks complete but there were database errors
when closing the steps and jobs. This patch updates the periodic
job deletion to delete such jobs.

Change-Id: Iae00d615bff79f42d8428b867f1816d6e0aa9a72
Bug-Url: https://bugzilla.redhat.com/1040952
Signed-off-by: c5542eaf646591383f6b59a9b598fa7b32c0cb99@redhat.com <c5542eaf646591383f6b59a9b598fa7b32c0cb99@redhat.com>

walteryang47/ovirt-engine,zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,eayun/ovirt-engine,yingyun001/ovirt-engine,eayun/ovirt-engine,OpenUniversity/ovirt-engine,zerodengxinchao/ovirt-engine,eayun/ovirt-engine,yapengsong/ovirt-engine,zerodengxinchao/ovirt-engine,eayun/ovirt-engine,OpenUniversity/ovirt-engine,yapengsong/ovirt-engine,zerodengxinchao/ovirt-engine,yingyun001/ovirt-engine,yingyun001/ovirt-engine,yapengsong/ovirt-engine,yapengsong/ovirt-engine,walteryang47/ovirt-engine,OpenUniversity/ovirt-engine,yingyun001/ovirt-engine,halober/ovirt-engine,walteryang47/ovirt-engine,walteryang47/ovirt-engine,OpenUniversity/ovirt-engine,halober/ovirt-engine,walteryang47/ovirt-engine,halober/ovirt-engine,yingyun001/ovirt-engine,yapengsong/ovirt-engine,OpenUniversity/ovirt-engine,halober/ovirt-engine,eayun/ovirt-engine