Fix Resque::Failure.each when order id 'desc'.
There was a bug with ordering IDs when going through the list in
reverse order.
This solution isn't really ideal, because ordering is still weird, but
at least it's not broken.
For more information:
https://github.com/resque/resque/issues/1172
Bug seems to have been introduced here:
10912efdcec91de7486e273f203c884db5f523f8
Attempted fix here, with its own bugs:
https://github.com/resque/resque/pull/1206