[stable/postgresql] Change regex looking for rolling tags (#14265)

Signed-off-by: Carlos Rodriguez Hernandez <crhernandez@bitnami.com>

stable/postgresql/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 name: postgresql
-version: 5.1.1
+version: 5.1.2
 appVersion: 11.3.0
 description: Chart for PostgreSQL, an object-relational database management system (ORDBMS) with an emphasis on extensibility and on standards-compliance.
 keywords:

stable/postgresql/templates/NOTES.txt

@@ -42,7 +42,7 @@ To connect to your database from outside the cluster execute the following comma
 
 {{- end }}
 
-{{- if and (contains "bitnami/" .Values.image.repository) (not (.Values.image.tag | regexFind "-r\\d+$")) }}
+{{- if and (contains "bitnami/" .Values.image.repository) (not (.Values.image.tag | toString | regexFind "-r\\d+$|sha256:")) }}
 
 WARNING: Rolling tag detected ({{ .Values.image.repository }}:{{ .Values.image.tag }}), please note that it is strongly recommended to avoid using rolling tags in a production environment.
 +info https://docs.bitnami.com/containers/how-to/understand-rolling-tags-containers/