[gimp] app: gimp_spin_scale_change_value(): remove "+ lower" from step calculation

[Michael Natterer <mitch src gnome org>]

commit 6dd463fb02acaa2d83935dd22ec32eb716ed07da
Author: Michael Natterer <mitch gimp org>
Date:   Mon Apr 18 21:21:45 2011 +0200

    app: gimp_spin_scale_change_value(): remove "+ lower" from step calculation
    
    It was never noticed because lower is 0.0 or 1.0 in all use cases.

 app/widgets/gimpspinscale.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/app/widgets/gimpspinscale.c b/app/widgets/gimpspinscale.c
index a85b300..010c686 100644
--- a/app/widgets/gimpspinscale.c
+++ b/app/widgets/gimpspinscale.c
@@ -368,7 +368,7 @@ gimp_spin_scale_change_value (GtkWidget *widget,
       gdouble diff;
       gdouble step;
 
-      step = ((upper - lower) + lower) / width / 10.0;
+      step = (upper - lower) / width / 10.0;
 
       diff = x - private->start_x;