Disable warnerrors=true in setup.cfg
Disable warnerrors=true in setup.cfg

The upcoming `pbr` release will make this flag effective and it may
result in broken tests and/or gate jobs. Disable for now till the next
release is out so we can re-enable it later and manage possible errors
alltogether.

Change-Id: Ic483121ff850319838d6b33e39059e6bdda9a88b

openstack/zaqar,openstack/zaqar,openstack/zaqar,openstack/zaqar