Replace the deprecated nova_metadata_ip

As [1], the option nova_metadata_ip has been deprecated and
we can use nova_metadata_host instead. This patch makes devstack
do it.

[1]: http://git.openstack.org/cgit/openstack/neutron/tree/neutron/conf/agent/metadata/config.py#n49

Change-Id: Ifda43ec8c7743af6acdd3003c55c081ef5b1311c
diff --git a/lib/neutron b/lib/neutron
index 21c8d4c..c5839f5 100644
--- a/lib/neutron
+++ b/lib/neutron
@@ -243,7 +243,7 @@
         cp $NEUTRON_DIR/etc/metadata_agent.ini.sample $NEUTRON_META_CONF
 
         iniset $NEUTRON_META_CONF DEFAULT debug $ENABLE_DEBUG_LOG_LEVEL
-        iniset $NEUTRON_META_CONF DEFAULT nova_metadata_ip $SERVICE_HOST
+        iniset $NEUTRON_META_CONF DEFAULT nova_metadata_host $SERVICE_HOST
         iniset $NEUTRON_META_CONF DEFAULT metadata_workers $API_WORKERS
         # TODO(ihrachys) do we really need to set rootwrap for metadata agent?
         configure_root_helper_options $NEUTRON_META_CONF