Fix a compilation error caused by some recent changes on glyph.hpp. https://tracker.physiomeproject.org/show_bug.cgi?id=3955
Fix a compilation error caused by some recent changes on glyph.hpp. https://tracker.physiomeproject.org/show_bug.cgi?id=3955

OpenCMISS/zinc,hsorby/zinc,hsorby/zinc,hsorby/zinc,OpenCMISS/zinc,hsorby/zinc,OpenCMISS/zinc,OpenCMISS/zinc