pki: backup previous ca when creating new one
pki: backup previous ca when creating new one

Change-Id: Ie4111dee70ea746dbb481d0a7597898ad51ec13d
Signed-off-by: Alon Bar-Lev <2e3ceb4d37adc6ae3ccc00d3646e0e0a036ace03@redhat.com>

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