GeoModelSvc.cxx: patched to work with GeoModel 5

Casted away the constness of the tree top constructed by GeoModelIO in order
to have the same code work for both old-style and the new-style detector
description systems

DetectorDescription/GeoModel/GeoModelSvc/src/GeoModelSvc.cxx

@@ -20,6 +20,7 @@
 #include "AthenaKernel/ClassID_traits.h"
 #include "SGTools/DataProxy.h"
 #include "PathResolver/PathResolver.h"
+#include "CxxUtils/checker_macros.h"
 
 #include "RDBAccessSvc/IRDBAccessSvc.h"
 #include "RDBAccessSvc/IRDBRecordset.h"
@@ -175,7 +176,7 @@ StatusCode GeoModelSvc::geoInit()
       return StatusCode::FAILURE;
     }
     m_sqliteReader = std::make_unique<GeoModelIO::ReadGeoModel>(m_sqliteDbManager.get());
-    GeoVPhysVol* vWorldPhys = m_sqliteReader->buildGeoModel();
+    GeoVPhysVol* vWorldPhys ATLAS_THREAD_SAFE = const_cast<GeoVPhysVol*>(m_sqliteReader->buildGeoModel());
     worldPhys = dynamic_cast<GeoPhysVol*>(vWorldPhys);
     if(!worldPhys) {
       ATH_MSG_FATAL("Having Full Physical Volumes as World Volumes not supported!");