feat (molgenis-vault): Switch backup storage to s3.

We can host s3 compatible storage locally by deploying the stable/minio chart.
Ran into https://github.com/coreos/etcd-operator/issues/1980 and therefore downgrade the backup and restore operator images to 0.8.3.

molgenis-vault/templates/backup-cronjob.yaml

@@ -1,4 +1,3 @@
-{{- if .Values.backupJob.enable }}
 # cronjob that creates etcdbackups using the etcd backup serviceaccount
 apiVersion: batch/v1beta1
 kind: CronJob
@@ -27,5 +26,4 @@ spec:
           volumes:
           - name: backup-config
             configMap:
-              name: backup-config
-{{- end }}
+              name: backup-config