[1.2.X] Fixed #14432 -- Added an import statement which was previously implied...

[1.2.X] Fixed #14432 -- Added an import statement which was previously implied in tutorial 3's URLconf to make it as explicit as possible for new users. Thanks to gorus for the report and andrews for the patch.

Backport of [14302] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14303 bcc190cf-cafb-0310-a4f2-bffc1f526a37