Add zuul/zuul-client to gerritbot
Add zuul/zuul-client to gerritbot

The repo zuul-client was recently created but not added to gerritbot,
add it now.

To avoid this in the future, use a regex to include all repos in the
zuul namespace.

Change-Id: I20ee1a2d55fe9c83ea4f5e948b810ad4c06862aa

openstack-infra/project-config,openstack-infra/project-config