Fixed a documentation typo on the widget page.

Author: tsaylor

docs/ref/forms/widgets.txt

@@ -75,7 +75,7 @@ changing :attr:`ChoiceField.choices` will update :attr:`Select.choices`. For
 example::
 
  >>> from django import forms
- >>> CHOICES = (('1', 'First',), ('2', 'Second',)))
+ >>> CHOICES = (('1', 'First',), ('2', 'Second',))
  >>> choice_field = forms.ChoiceField(widget=forms.RadioSelect, choices=CHOICES)
  >>> choice_field.choices
  [('1', 'First'), ('2', 'Second')]