[gnome-games] sudoku: Fix broken cell clear button

[Robert Ancell <rancell src gnome org>]

commit 64d12bcded44a47d920a5fc8709f376763de6c08
Author: Robert Ancell <robert ancell canonical com>
Date:   Thu Aug 19 10:44:06 2010 +1000

    sudoku: Fix broken cell clear button

 gnome-sudoku/src/lib/number_box.py |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gnome-sudoku/src/lib/number_box.py b/gnome-sudoku/src/lib/number_box.py
index dc38dc3..e5dee00 100644
--- a/gnome-sudoku/src/lib/number_box.py
+++ b/gnome-sudoku/src/lib/number_box.py
@@ -307,6 +307,8 @@ class NumberBox (gtk.Widget):
         newval = num_selector.get_value()
         if newval:
             self.set_text_interactive(str(newval))
+        else:
+            self.set_text_interactive('')            
 
     def show_number_picker (self):
         w = gtk.Window(type = gtk.WINDOW_POPUP)