[nanny] Don't remove source of update_proxy_settings if not exists

[Roberto Majadas <telemaco src gnome org>]

commit 6b86a94443248d84071c3763f2c1ebb788f44c56
Author: Roberto Majadas <roberto majadas openshine com>
Date:   Mon Nov 1 20:12:16 2010 +0100

    Don't remove source of update_proxy_settings if not exists

 daemon/src/Win32WebContentFiltering.py |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/daemon/src/Win32WebContentFiltering.py b/daemon/src/Win32WebContentFiltering.py
index 9790a51..f0efc46 100644
--- a/daemon/src/Win32WebContentFiltering.py
+++ b/daemon/src/Win32WebContentFiltering.py
@@ -89,8 +89,9 @@ class Win32WebContentFiltering(gobject.GObject) :
         print "Stop Win32 Web Content Filtering"
         for uid in self.services.keys() :
             self.__stop_proxy(self.quarterback, uid)
-
-        gobject.source_remove(self.update_proxy_settings_hd)
+        
+        if self.update_proxy_settings_hd != None :
+            gobject.source_remove(self.update_proxy_settings_hd)
         self.proxy_helper.clean_all_proxy_conf()
 
     def __start_proxy(self, quarterback, uid):