Add stderr exclusion for switch to Geant4 units

ROOT prints a warning when we select explicitly a system of units. We already had the exclusion for Changing system of units to ROOT units, but we didn't have it for Changing system of units to Geant4 units.

added lhcb-head-2 label

approved this merge request

merged

mentioned in commit 3c5a2bd9

mentioned in issue DaVinci#89 (closed)