Remove duplicate command example

pkg/kubectl/cmd/portforward.go

@@ -59,10 +59,7 @@ var (
 		kubectl port-forward mypod 8888:5000
 
 		# Listen on a random port locally, forwarding to 5000 in the pod
-		kubectl port-forward mypod :5000
-
-		# Listen on a random port locally, forwarding to 5000 in the pod
-		kubectl port-forward mypod 0:5000`))
+		kubectl port-forward mypod :5000`))
 )
 
 func NewCmdPortForward(f cmdutil.Factory, cmdOut, cmdErr io.Writer) *cobra.Command {