[stable/postgresql] Fix invalid StatefulSet volumeClaimTemplates annotations if empty. (#9115)

Signed-off-by: Cédric de Saint Martin <cdesaintmartin@wiremind.fr>

stable/postgresql/Chart.yaml

@@ -1,5 +1,5 @@
 name: postgresql
-version: 2.5.0
+version: 2.5.1
 appVersion: 10.6.0
 description: Chart for PostgreSQL, an object-relational database management system (ORDBMS) with an emphasis on extensibility and on standards-compliance.
 keywords:

stable/postgresql/templates/statefulset.yaml

@@ -163,10 +163,12 @@ spec:
   volumeClaimTemplates:
     - metadata:
         name: data
+      {{- with .Values.persistence.annotations }}
         annotations:
-        {{- range $key, $value := .Values.persistence.annotations }}
+        {{- range $key, $value := . }}
           {{ $key }}: {{ $value }}
         {{- end }}
+      {{- end }}
       spec:
         accessModes:
         {{- range .Values.persistence.accessModes }}