gtk: Use font_size

gtk/gtk-3.0.ini.j2

@@ -0,0 +1,15 @@
+[Settings]
+gtk-theme-name=Breeze
+gtk-icon-theme-name=breeze-dark
+gtk-font-name=DejaVu Sans {{ machine.font_size|int - 1 }}
+gtk-cursor-theme-name=breeze_cursors
+gtk-cursor-theme-size=0
+gtk-toolbar-style=GTK_TOOLBAR_BOTH
+gtk-toolbar-icon-size=GTK_ICON_SIZE_LARGE_TOOLBAR
+gtk-button-images=1
+gtk-menu-images=1
+gtk-enable-event-sounds=1
+gtk-enable-input-feedback-sounds=1
+gtk-xft-antialias=1
+gtk-xft-hinting=1
+gtk-xft-hintstyle=hintfull