chart: support imagePullSecrets on tower-backend

templates/backend-deployment.yaml

@@ -19,6 +19,10 @@ spec:
         odoosky.io/role: backend
     spec:
       serviceAccountName: tower
+      {{- with .Values.backend.imagePullSecrets }}
+      imagePullSecrets:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
       containers:
         - name: tower
           image: "{{ .Values.backend.image.repository }}:{{ .Values.backend.image.tag }}"