(GH-3238) fix FlatSlider height usage (works now together with vertical and horizontal content alignement)
(GH-3238) fix FlatSlider height usage (works now together with vertical and horizontal content alignement)

ye4241/MahApps.Metro,Evangelink/MahApps.Metro,MahApps/MahApps.Metro,batzen/MahApps.Metro,xxMUROxx/MahApps.Metro