LinGui: Fix deprecated GtkHScale
Fixing this deprecation makes the LinGui incompatible with versions
of gtk prior to 2.16. Too bad for you if you are using such and ancient gtk.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5970 b64f7644-9d1e-0410-96f1-a4d463321fa5