Checkmk Werk 13404: mk_docker.py: diskstat: do not discovery devices without counters

ID: 13404 Title: mk_docker.py: diskstat: do not discovery devices without counters Component: Checks & agents Level: 1 Class: Bug fix Version: 2.1.0i1 Before this change the discovery behaviour of the diskstat check was dependent on the source of the data: When running an agent inside a docker container, devices without counters where not discovered, when running the mk_docker.py agent plugin those devices where discovered. With this Werk devices without counters are no longer discovered with mk_docker.py