[kong] remove default controller binary arg

Remove the hard-coded /kong-ingress-controller arg from the controller
container arguments.

This argument is no longer correct as of 2.0, where the binary is
instead /manager. It is apparently ignored. Removing it does not
interfere with normal start or configured arguments

This argument appears unnecessary for older versions of the controller.
We've had /kong-ingress-controller or /manager as our entrypoint since
we created the Dockerfile, so it's always invoked anyway.

Removing this arg allows for alternative images that do not use the
contorller binary and whose binary /is/ confused by the extra argument
(namely Delve-based images).

charts/kong/templates/_helpers.tpl

@@ -568,7 +568,6 @@ Note that this is a string, not a boolean, because templates vov
   securityContext:
 {{ toYaml .Values.containerSecurityContext | nindent 4 }}  
   args:
-  - /kong-ingress-controller
   {{ if .Values.ingressController.args}}
   {{- range $val := .Values.ingressController.args }}
   - {{ $val }}