Use const for kube-system namespace

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>

pkg/cluster/https.go

@@ -17,6 +17,7 @@ import (
 	"github.com/rancher/k3s/pkg/version"
 	"github.com/rancher/wrangler-api/pkg/generated/controllers/core"
 	"github.com/sirupsen/logrus"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 func (c *Cluster) newListener(ctx context.Context) (net.Listener, http.Handler, error) {
@@ -84,5 +85,5 @@ func tlsStorage(ctx context.Context, dataDir string, runtime *config.ControlRunt
 	cache := memory.NewBacked(fileStorage)
 	return kubernetes.New(ctx, func() *core.Factory {
 		return runtime.Core
-	}, "kube-system", ""+version.Program+"-serving", cache)
+	}, metav1.NamespaceSystem, version.Program+"-serving", cache)
 }