Fixed #23785 -- Typo in docs/releases/1.6.txt

Django 1.6 starts a process to correct this inconsistency. The ``future``

template library provides alternate implementations of :ttag:`cycle` and

:ttag:`firstof` that autoescape their inputs. If you're using these tags,

you're encourage to include the following line at the top of your templates to

you're encouraged to include the following line at the top of your templates to

enable the new behavior::

    {% load cycle from future %}