Fix variable naming bug in OpenStack CCM (#5702)

roles/kubernetes-apps/external_cloud_controller/openstack/templates/external-openstack-cloud-config.j2

@@ -43,5 +43,5 @@ floating-subnet-id={{ external_openstack_lbaas_floating_subnet_id }}
 manage-security-groups={{ external_openstack_lbaas_manage_security_groups }}
 {% endif %}
 {% if external_openstack_lbaas_internal_lb is defined %}
-internal-lb={{ external_openstack_internal_lb }}
+internal-lb={{ external_openstack_lbaas_internal_lb }}
 {% endif %}