Configure os-vif ovsdb_connection

This patch set the os-vif "ovsdb_connection" configuration option so it
can connect to the local OVSDB. By default, this option points to
tcp:127.0.0.1:6640 and would fail if SERVICE_IP_VERSION == 6.

Also, if SERVICE_IP_VERSION is an IPv6 address, it should be wraped with
square brackets for it to work.

Change-Id: Ie6eec4e140c7464936cf0b0c6307026a94c9f4ee
Signed-off-by: Lucas Alvares Gomes <lucasagomes@gmail.com>
diff --git a/lib/neutron_plugins/ovn_agent b/lib/neutron_plugins/ovn_agent
index 84df918..b7330db 100644
--- a/lib/neutron_plugins/ovn_agent
+++ b/lib/neutron_plugins/ovn_agent
@@ -91,7 +91,10 @@
 OVN_META_CONF=$NEUTRON_CONF_DIR/neutron_ovn_metadata_agent.ini
 OVN_META_DATA_HOST=${OVN_META_DATA_HOST:-$(ipv6_unquote $SERVICE_HOST)}
 
-OVSDB_SERVER_LOCAL_HOST=$SERVICE_LOCAL_HOST
+export OVSDB_SERVER_LOCAL_HOST=$SERVICE_LOCAL_HOST
+if [[ "$SERVICE_IP_VERSION" == 6 ]]; then
+    OVSDB_SERVER_LOCAL_HOST=[$OVSDB_SERVER_LOCAL_HOST]
+fi
 
 OVN_IGMP_SNOOPING_ENABLE=$(trueorfalse False OVN_IGMP_SNOOPING_ENABLE)