Enable keystoneauth for octavia_identity

This is a follow up for a change that set `use_keystoneauth: true`
for admin_identity.

Related PROD: PROD-13344

Change-Id: I7c09b837db074092cca2ad31b1136c0380fa9774
diff --git a/keystone/client/service/octavia.yml b/keystone/client/service/octavia.yml
index 4e14217..0382345 100644
--- a/keystone/client/service/octavia.yml
+++ b/keystone/client/service/octavia.yml
@@ -36,3 +36,4 @@
             host: ${_param:keystone_service_host}
             port: 5000
             region_name: ${_param:openstack_region}
+            use_keystoneauth: true