Checkmk Werk 10217: check_mk_agent.linux: Fixed docker_container_mem section

ID: 10217 Title: check_mk_agent.linux: Fixed docker_container_mem section Component: Checks & agents Level: 1 Class: Bug fix Version: 1.7.0i1 Empty output of "<<<ps_lnx>>>" causes an incorrect format in the agent output of the next section, eg. "[header] <<<docker_container_mem>>>". The services of {{ps_lnx}} displayed the error message {{Exception: KeyError}}.