Make build more robust to missing GIF library
Make build more robust to missing GIF library

micler/oiio,cwilling/oiio,YangYangTL/oiio,micler/oiio,scott-wilson/oiio,cwilling/oiio,sambler/oiio,bdeluca/oiio,mcanthony/oiio,OpenImageIO/oiio,micler/oiio,sambler/oiio,lgritz/oiio,OpenImageIO/oiio,lgritz/oiio,mcanthony/oiio,cwilling/oiio,bdeluca/oiio,micler/oiio,sambler/oiio,bdeluca/oiio,scott-wilson/oiio,scott-wilson/oiio,mcanthony/oiio,OpenImageIO/oiio,scott-wilson/oiio,YangYangTL/oiio,mcanthony/oiio,YangYangTL/oiio,bdeluca/oiio,lgritz/oiio,lgritz/oiio,sambler/oiio,OpenImageIO/oiio,cwilling/oiio,YangYangTL/oiio