Fix LoadBalancerMember creation

When creating loadbalancer member, subnet not found error occurred.
This commit fixes it.
If subnet is not given, LBaaS uses the vip_subnet_id parameter value for
the subnet UUID.

Author: hidekazuna

pkg/cloud/services/loadbalancer/loadbalancer.go

@@ -217,7 +217,6 @@ func (s *Service) ReconcileLoadBalancerMember(clusterName string, machine *clust
 	s.logger.Info("Reconciling loadbalancer", "name", loadBalancerName)
 
 	lbID := openStackCluster.Status.Network.APIServerLoadBalancer.ID
-	subnetID := openStackCluster.Status.Network.Subnet.ID
 	portList := []int{int(openStackCluster.Spec.ControlPlaneEndpoint.Port)}
 	portList = append(portList, openStackCluster.Spec.APIServerLoadBalancerAdditionalPorts...)
 	for _, port := range portList {
@@ -268,7 +267,6 @@ func (s *Service) ReconcileLoadBalancerMember(clusterName string, machine *clust
 			Name:         name,
 			ProtocolPort: port,
 			Address:      ip,
-			SubnetID:     subnetID,
 		}
 
 		if err := waitForLoadBalancerActive(s.logger, s.loadbalancerClient, lbID); err != nil {