Fixed var init order warning

LHCbG4Tests/G4GammaToDiLeptonConversionTest/include/DetectorConstruction.hh

@@ -80,8 +80,8 @@ class DetectorConstruction : public G4VUserDetectorConstruction
      G4VPhysicalVolume*    fP_Box;
      G4LogicalVolume*      fL_Box;
 
-     G4double              fBoxDepth;
      G4double              fBoxXY;
+     G4double              fBoxDepth;
      G4Material*           fMaterial;
      G4UniformMagField*    fMagField;
      G4UserLimits*         fUserLimits;