Checkmk Werk 12289: Backup: Fix adding / editing backup jobs with manual schedule

ID: 12289 Title: Backup: Fix adding / editing backup jobs with manual schedule Component: Setup Level: 1 Class: Bug fix Version: 2.1.0i1 When adding or editing backup jobs with a "manual schedule" configuration this lead to an exception "TypeError (argument of type 'NoneType' is not iterable)" in previous 2.0.0 releases.