update constraint for oslo.privsep to new release 2.0.0
update constraint for oslo.privsep to new release 2.0.0

Depends-on:Ibbab926898aace120592dc8453f34d12b4a0ed9a
Change-Id: Ica47b37f12f12df739f7d64b133406acfa14fd04

openstack/rpm-packaging,openstack/rpm-packaging