Add missing config option os_auth_url

Without this option will appear as an error:
Skip interval_task because Keystone error:
Authorization Failed: Unable to establish connection to
http://localhost:5000/v2.0/tokens

Closes-Bug: #1325383

Change-Id: I42fe92596d9d475f2c5b2a6aa6b49d2b7b821c54
diff --git a/lib/ceilometer b/lib/ceilometer
index 286f199..eef6740 100644
--- a/lib/ceilometer
+++ b/lib/ceilometer
@@ -163,6 +163,7 @@
     iniset $CEILOMETER_CONF service_credentials os_username ceilometer
     iniset $CEILOMETER_CONF service_credentials os_password $SERVICE_PASSWORD
     iniset $CEILOMETER_CONF service_credentials os_tenant_name $SERVICE_TENANT_NAME
+    iniset $CEILOMETER_CONF service_credentials os_auth_url $OS_AUTH_URL
 
     iniset $CEILOMETER_CONF keystone_authtoken identity_uri $KEYSTONE_AUTH_URI
     iniset $CEILOMETER_CONF keystone_authtoken admin_user ceilometer