Comment 12 for bug 1354709

I apologize for a typo in the patch submitted in the previous comment. The new lines should of course be

                         if os.path.exists(f):
                            os.remove(f)

("f" not "dest_file").

I have reported this problem and patch in a bug report on update-notifier at
https://bugs.launchpad.net/bugs/1425118