common-tasks: test-set-nodepool-vars: Populate fact for EPEL mirror

We should use the EPEL nodepool mirror when available in order to
improve the reliability of the CentOS jobs.

Change-Id: I565e45159b5979e5e161c749500d0525903e156a

common-tasks/test-set-nodepool-vars.yml

@@ -30,6 +30,7 @@
         echo "opensuse_mirror=${NODEPOOL_OPENSUSE_MIRROR}"
         echo "pip_default_index=${NODEPOOL_PYPI_MIRROR}"
         echo "pip_wheel_mirror=${NODEPOOL_WHEEL_MIRROR}"
+        echo "centos_epel_mirror=${NODEPOOL_EPEL_MIRROR}"
         if [[ ${NODEPOOL_PYPI_MIRROR} == *.ovh.* ]]; then
           echo "nova_virt_type=qemu"
         fi

zuul.d/jobs.yaml

@@ -230,6 +230,8 @@
     name: openstack-ansible-functional-centos-7
     parent: openstack-ansible-functional
     nodeset: centos-7
+    # Temporary nv until https://review.openstack.org/#/c/574382/ gets in
+    voting: false
 
 - job:
     name: openstack-ansible-functional-centos-7-nv