[docs] Bug in re example

[Eli Bendersky]

>
> Herman, thank you for the report. I've opened Issue 12146 in the
> Python tracker (http://bugs.python.org/issue12146) to track this.
>
> Eli
>

And I've just noticed these were already fixed by Georg, committed in
revisions 538a6b23b18f and 12a2c1085621

Eli