Fix delete pool lead to panic

1) seems we don't need port 22, have no idea why use here
2) when pool not exist, should check and ignore following actions

Author: jichenjc

pkg/cloud/openstack/services/networking/loadbalancer.go

@@ -274,14 +274,18 @@ func (s *Service) DeleteLoadBalancerMember(clusterName string, machine *clusterv
 
 	lbID := clusterProviderStatus.Network.APIServerLoadBalancer.ID
 
-	for _, port := range []int{22, 6443} {
+	for _, port := range []int{6443} {
 		lbPortObjectsName := fmt.Sprintf("%s-%d", loadBalancerName, port)
 		name := lbPortObjectsName + "-" + machine.Name
 
 		pool, err := checkIfPoolExists(s.client, lbPortObjectsName)
 		if err != nil {
 			return err
 		}
+		if pool == nil {
+			klog.Infof("Pool %s does not exist", lbPortObjectsName)
+			continue
+		}
 
 		lbMember, err := checkIfLbMemberExists(s.client, pool.ID, name)
 		if err != nil {