Fix error when calling get_values on an ingredient directly
Fix error when calling get_values on an ingredient directly

This happens e.g. with search engines

DeveloperMal/wger,DeveloperMal/wger,petervanderdoes/wger,kjagoo/wger_stark,wger-project/wger,kjagoo/wger_stark,kjagoo/wger_stark,kjagoo/wger_stark,petervanderdoes/wger,wger-project/wger,rolandgeider/wger,DeveloperMal/wger,petervanderdoes/wger,rolandgeider/wger,rolandgeider/wger,petervanderdoes/wger,wger-project/wger,DeveloperMal/wger,wger-project/wger,rolandgeider/wger