Add 'system.galera.server.database.neutron' on database nodes

Related to https://gerrit.mcp.mirantis.com/#/c/29231/

Change-Id: I7b322d0b86a3d5fae6da1f828599530cf0626d50
diff --git a/classes/cluster/sl-pike-dvr/openstack/control.yml b/classes/cluster/sl-pike-dvr/openstack/control.yml
index f0ac140..8a72cf2 100644
--- a/classes/cluster/sl-pike-dvr/openstack/control.yml
+++ b/classes/cluster/sl-pike-dvr/openstack/control.yml
@@ -31,6 +31,7 @@
 - system.galera.server.database.heat
 - system.galera.server.database.keystone
 - system.galera.server.database.nova
+- system.galera.server.database.neutron
 - system.prometheus.relay
 - system.prometheus.server.standalone
 - system.prometheus.server.target.federation