Move OS Dashboard to ctl nodes in OS HA OVS

Change-Id: I2aef7d99373152bb192d9b66e93da3a74afe8639
diff --git a/classes/cluster/os_ha_ovs/openstack/dashboard.yml b/classes/cluster/os_ha_ovs/openstack/dashboard.yml
index c790ad0..ddddaa9 100644
--- a/classes/cluster/os_ha_ovs/openstack/dashboard.yml
+++ b/classes/cluster/os_ha_ovs/openstack/dashboard.yml
@@ -3,7 +3,7 @@
 - system.linux.system.repo.mcp.openstack
 - system.linux.system.repo.mcp.extra
 - system.linux.system.repo.saltstack.xenial
-- system.horizon.server.single
+- system.horizon.server.cluster
 - cluster.os_ha_ovs
 parameters:
   _param: