Patch is a bit nasty and not maintainer friendly, but it does
make Gtk+3 compile without libepoxy (which means without OpenGL
dev files).
(From OE-Core rev: 82bedec89a86902456e924a3ac2f233b6a069dea)
Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>