Remove the delete propagation flag

In it's current state it now takes me about 25 seconds for the `kn delete`
to complete. Before knative#682 it used to be
almost immediate. This is because we now pass in the
`DeletePropagationBackground` flag. I believe this is a mistake, not only
because of the 20+ seconds of additional time to delete things, but IMO
the CLI should talk to the server in the same way regardless of the --wait
flag. That flag should just be a CLI thing to indicate if the user wants the CLI
to wait for the server to complete but not HOW the server should do the delete.

Signed-off-by: Doug Davis <[email protected]>

pkg/serving/v1/client.go

@@ -262,25 +262,25 @@ func updateServiceWithRetry(cl KnServingClient, name string, updateFunc serviceU
 // For `timeout == 0` delete is performed async without any wait.
 func (cl *knServingClient) DeleteService(serviceName string, timeout time.Duration) error {
 	if timeout == 0 {
-		return cl.deleteService(serviceName, v1.DeletePropagationBackground)
+		return cl.deleteService(serviceName)
 	}
 	waitC := make(chan error)
 	go func() {
 		waitForEvent := wait.NewWaitForEvent("service", cl.WatchService, func(evt *watch.Event) bool { return evt.Type == watch.Deleted })
 		err, _ := waitForEvent.Wait(serviceName, wait.Options{Timeout: &timeout}, wait.NoopMessageCallback())
 		waitC <- err
 	}()
-	err := cl.deleteService(serviceName, v1.DeletePropagationForeground)
+	err := cl.deleteService(serviceName)
 	if err != nil {
 		return err
 	}
 	return <-waitC
 }
 
-func (cl *knServingClient) deleteService(serviceName string, propagationPolicy v1.DeletionPropagation) error {
+func (cl *knServingClient) deleteService(serviceName string) error {
 	err := cl.client.Services(cl.namespace).Delete(
 		serviceName,
-		&v1.DeleteOptions{PropagationPolicy: &propagationPolicy},
+		&v1.DeleteOptions{},
 	)
 	if err != nil {
 		return clienterrors.GetError(err)