Avoid deadlock between SGSvcImpl and IOVDbSvc.
requested to merge goetz/athena:ATLASRECTS-6894_master_fix_deadloack_between_SGImplSvc_and_IOVSbSvc into master
- Avoid deadlock between SGSvcImpl and IOVDbSvc.
- Also moved consistency check to a function and perform consistency check only of something has changed.
Closes ATLASRECTS-6894
Edited by Goetz Gaycken