fix(chart:k8up) labels for Dashboard

Signed-off-by: André Frimberger <andre@intellisoft.de>

charts/k8up/templates/grafana-dashboard.yaml

@@ -5,7 +5,7 @@ metadata:
   namespace: {{ default .Release.Namespace .Values.metrics.grafanaDashboard.namespace }}
   labels:
     {{- include "k8up.labels" . | nindent 4 }}
-    {{- with .Values.metrics.prometheusRule.additionalLabels }}
+    {{- with .Values.metrics.grafanaDashboard.additionalLabels }}
     {{- toYaml . | nindent 4 }}
     {{- end }}
 data: