[stable/centrifugo] Helm3: Do not render ClusterIP if it is empty (#19439)

Signed-off-by: Vladimir Chernyshev <volch5@gmail.com>

stable/centrifugo/Chart.yaml

@@ -1,5 +1,5 @@
 apiVersion: v1
-version: 3.1.0
+version: 3.1.1
 appVersion: 2.1.0
 description: Centrifugo is a real-time messaging server.
 name: centrifugo

stable/centrifugo/templates/service.yaml

@@ -13,7 +13,9 @@ metadata:
   name: {{ include "centrifugo.fullname" . }}
 spec:
   type: "{{ .Values.service.type }}"
+{{- if .Values.service.clusterIP }}
   clusterIP: "{{ .Values.service.clusterIP }}"
+{{- end }}
 {{- if .Values.service.externalIPs }}
   externalIPs:
 {{ toYaml .Values.service.externalIPs | indent 4 }}