This patch updates the graphite targets queried for the neutron-lib
grafana dashboard. These targets are important for understanding our
pre-release health. For more details see discussion started at [1].
[1] http://eavesdrop.openstack.org/irclogs/%23openstack-infra/
%23openstack-infra.2018-04-23.log.html#t2018-04-23T16:16:44
Change-Id: Ie0ef7102c20b60558cb758aff607e87e5bbb9047