Add the required version of the main DD4hep compact XML file
This fixes the DD4hep in Gauss after the latest changes in the LHCb project (LHCb!3982 (merged)) where the version of the main compact XML file cannot be blank anymore.
This fixes the DD4hep in Gauss after the latest changes in the LHCb project (LHCb!3982 (merged)) where the version of the main compact XML file cannot be blank anymore.