Add missing include.
Add missing include.

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