Work-around for GCC 8 messing up the unit test for `dip::PhysicalQuantity::Normalize`.
Work-around for GCC 8 messing up the unit test for `dip::PhysicalQuantity::Normalize`.

DIPlib/diplib,DIPlib/diplib,DIPlib/diplib,DIPlib/diplib,DIPlib/diplib,DIPlib/diplib