Store Peppyrus message using service instance instead of class

Closes #14990
(grafted from 85c2d0b69b01250cd2c7c21eb16a4b86c550edc3)

--HG--
branch : 8.0

modules/edocument_peppol_peppyrus/routes.py

@@ -32,7 +32,7 @@ def incoming(request, pool, identifier):
         abort(HTTPStatus.NOT_FOUND)
 
     message = json.loads(request.data)
-    Service.peppyrus_store(message)
+    service.peppyrus_store(message)
     return Response(status=HTTPStatus.NO_CONTENT)