gerrit: use pcloud oauth provider instead of auth-proxy

Change-Id: I555a05ca00c90e84d3c82f31ccd53a220feff344
diff --git a/charts/gerrit/templates/gerrit.configmap.yaml b/charts/gerrit/templates/gerrit.configmap.yaml
index 83c188c..cd1a6a9 100644
--- a/charts/gerrit/templates/gerrit.configmap.yaml
+++ b/charts/gerrit/templates/gerrit.configmap.yaml
@@ -1,5 +1,6 @@
 {{- $root := . -}}
 
+{{- if not .Values.gerrit.etc.existingConfigMapName }}
 apiVersion: v1
 kind: ConfigMap
 metadata:
@@ -28,6 +29,7 @@
       enabled = false
   {{- end }}
 ---
+{{- end }}
 apiVersion: v1
 kind: ConfigMap
 metadata: