Checkmk Werk 15253: Abort CMC startup if state file could not be read or parsed

ID: 15253 Title: Abort CMC startup if state file could not be read or parsed Component: cmc Level: 1 Class: Bug fix Version: 2.3.0b1 This avoids simply continuing and creating a new state file, which loses all comments, ad hoc downtimes, acknowledgements, etc. Note that it is still OK when there is no state file at all, which is e.g. the case when the CMC starts for the first time.