Fix Error.absolute_path logic

[Documentation](https://docs.python.org/2/library/collections.html#collections.deque.extendleft) says:
> extendleft(iterable)
> Extend the left side of the deque by appending elements from iterable. Note, the series of left appends results in reversing the order of elements in the iterable argument.

Reversing causes incorrect `absolute_path` behaviour. Here is the fix.