Without this a gtk+2 app appended to an image is going to look awful.
(From OE-Core rev: a01fd55ca0a93489170e8b1612f25ae3a3ed996e)
Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>