[gnome-themes-standard] column-header: fix unwanted border in last-child backdrop headers

[Cosimo Cecchi <cosimoc src gnome org>]

commit 36d9c6044c2228c7f0ee7b8bbb886e932a93b0f9
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Tue Aug 21 03:07:36 2012 +0200

    column-header: fix unwanted border in last-child backdrop headers

 themes/Adwaita/gtk-3.0/gtk-widgets-borders.css |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/themes/Adwaita/gtk-3.0/gtk-widgets-borders.css b/themes/Adwaita/gtk-3.0/gtk-widgets-borders.css
index 9394867..38abe46 100644
--- a/themes/Adwaita/gtk-3.0/gtk-widgets-borders.css
+++ b/themes/Adwaita/gtk-3.0/gtk-widgets-borders.css
@@ -149,7 +149,9 @@ column-header .button:active:hover {
 }
 
 column-header.button:backdrop,
-column-header .button:backdrop {
+column-header .button:backdrop,
+column-header.button:last-child:backdrop,
+column-header:last-child .button:backdrop {
     border-image: none;
     border-width: 0 1px 1px 0;
     border-radius: 0;