Fixed #11328 -- Added missing imports in the sample urls.py from Tutorial 3. Thanks to marcalj for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11021 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/intro/tutorial03.txt

@@ -82,6 +82,9 @@ Time for an example. Edit ``mysite/urls.py`` so it looks like this::
 
     from django.conf.urls.defaults import *
 
+    from django.contrib import admin
+    admin.autodiscover()
+
     urlpatterns = patterns('',
         (r'^polls/$', 'mysite.polls.views.index'),
         (r'^polls/(?P<poll_id>\d+)/$', 'mysite.polls.views.detail'),