Checkmk Werk 12051: API: fixing the list group endpoints for host_group, contact_group and service_group

ID: 12051 Title: API: fixing the list group endpoints for host_group, contact_group and service_group Component: Core & setup Level: 1 Class: Bug fix Version: 2.1.0i1 In the previous version, the list group endpoints for host_group, contact_group and service_group returned a 500 error when called. This werk fixes this behaviour.