Adapt compute node local.conf to OVN

The default Neutron configuration is now using OVN, but the multinode
lab was using an incompatible configuration:

    The q-agt/neutron-agt service must be disabled with OVN.

Change-Id: I518a739a3daac941880463cde6b47951331d0911
diff --git a/doc/source/guides/multinode-lab.rst b/doc/source/guides/multinode-lab.rst
index c0b3f58..f62e7a9 100644
--- a/doc/source/guides/multinode-lab.rst
+++ b/doc/source/guides/multinode-lab.rst
@@ -169,7 +169,7 @@
     MYSQL_HOST=$SERVICE_HOST
     RABBIT_HOST=$SERVICE_HOST
     GLANCE_HOSTPORT=$SERVICE_HOST:9292
-    ENABLED_SERVICES=n-cpu,q-agt,c-vol,placement-client
+    ENABLED_SERVICES=n-cpu,c-vol,placement-client,ovn-controller,ovs-vswitchd,ovsdb-server,q-ovn-metadata-agent
     NOVA_VNC_ENABLED=True
     NOVNCPROXY_URL="http://$SERVICE_HOST:6080/vnc_lite.html"
     VNCSERVER_LISTEN=$HOST_IP