[pitivi] mainwindow: Do not use variables that dp not exist

[Thibault Saunier <tsaunier src gnome org>]

commit 57674aa67063bebee3d1454a0637dbdacc190e6d
Author: Thibault Saunier <tsaunier gnome org>
Date:   Wed Oct 22 19:46:52 2014 +0200

    mainwindow: Do not use variables that dp not exist
    
    https://bugzilla.gnome.org/show_bug.cgi?id=739251

 pitivi/mainwindow.py |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/mainwindow.py b/pitivi/mainwindow.py
index c8396f7..90a1c98 100644
--- a/pitivi/mainwindow.py
+++ b/pitivi/mainwindow.py
@@ -266,8 +266,9 @@ class PitiviMainWindow(Gtk.ApplicationWindow, Loggable):
         self._menubutton = self.builder.get_object("menubutton")
 
         if Gtk.get_major_version() == 3 and Gtk.get_minor_version() < 13:
-            open_menu_image = builder.get_object("open_menu_image")
+            open_menu_image = self.builder.get_object("open_menu_image")
             open_menu_image.set_property("icon_name", "emblem-system-symbolic")
+
         self._menubutton_items = {}
         for widget in self.builder.get_object("menu").get_children():
             self._menubutton_items[Gtk.Buildable.get_name(widget)] = widget