Remove invalid kustomizeconfig from config/webhook

This change has no effect on the output of this kustomization because
the removed configuration was redundant. However, it fixes a bug which
can be triggered when using this kustomization as a base for another
kustomization.

kustomizeconfig contained 3 directives:

* nameReference
* namespace
* varReference

varReference remains required until vars are removed from this
kustomization.

nameReference is redundant because the specified configuration is
already in kustomize's defaults. However, nameReference is the important
transformation here.

namespace is incorrect. It directs the namespace transformer to update
webhooks/clientConfig/service/namespace. However, this is not the
intended function of the namespace transformer: it should only set the
namespace directly on objects and allow references to be updated
automatically by nameReference. Configuring it to update a reference
directly leaves kustomize with inconsistent internal state. Depending on
execution order this can cause a subsequent transformation to fail to
update the reference when it makes further changes to the Service
object.

Author: mdbooth

config/webhook/kustomizeconfig.yaml

@@ -1,25 +1,4 @@
-# the following config is for teaching kustomize where to look at when substituting vars.
-# It requires kustomize v2.1.0 or newer to work properly.
-nameReference:
-- kind: Service
-  version: v1
-  fieldSpecs:
-  - kind: MutatingWebhookConfiguration
-    group: admissionregistration.k8s.io
-    path: webhooks/clientConfig/service/name
-  - kind: ValidatingWebhookConfiguration
-    group: admissionregistration.k8s.io
-    path: webhooks/clientConfig/service/name
-
-namespace:
-- kind: MutatingWebhookConfiguration
-  group: admissionregistration.k8s.io
-  path: webhooks/clientConfig/service/namespace
-  create: true
-- kind: ValidatingWebhookConfiguration
-  group: admissionregistration.k8s.io
-  path: webhooks/clientConfig/service/namespace
-  create: true
-
+# This directive should be removed when vars are removed from this
+# kustomization
 varReference:
 - path: metadata/annotations