AETHER-1260 Better support of helm-kustomize for omec-control-plane chart

Change-Id: I24c22cbacca60e3b6c5c3bca7ec76c9c987c2b56
diff --git a/omec/omec-control-plane/templates/statefulset-mme.yaml b/omec/omec-control-plane/templates/statefulset-mme.yaml
index c0b6e82..0a47593 100644
--- a/omec/omec-control-plane/templates/statefulset-mme.yaml
+++ b/omec/omec-control-plane/templates/statefulset-mme.yaml
@@ -33,9 +33,9 @@
         {{ .Values.nodeSelectors.mme.label }}: {{ .Values.nodeSelectors.mme.value }}
     {{- end }}
       serviceAccountName: mme
-    {{- if .Values.images.credentials }}
+    {{- if hasKey .Values.images "pullSecrets" }}
       imagePullSecrets:
-        - name: {{ .Release.Name }}.registry
+{{ toYaml .Values.images.pullSecrets | indent 8 }}
     {{- end }}
       initContainers:
       - name: mme-load-sctp-module