Fixed #19605 - Removed unused url imports from doc examples.

Thanks sergzach for the suggestion.

docs/ref/contrib/admin/index.txt

@@ -1928,7 +1928,7 @@ In this example, we register the default ``AdminSite`` instance
 ``django.contrib.admin.site`` at the URL ``/admin/`` ::
 
     # urls.py
-    from django.conf.urls import patterns, url, include
+    from django.conf.urls import patterns, include
     from django.contrib import admin
 
     admin.autodiscover()
@@ -1944,7 +1944,7 @@ In this example, we register the ``AdminSite`` instance
 ``myproject.admin.admin_site`` at the URL ``/myadmin/`` ::
 
     # urls.py
-    from django.conf.urls import patterns, url, include
+    from django.conf.urls import patterns, include
     from myproject.admin import admin_site
 
     urlpatterns = patterns('',
@@ -1968,7 +1968,7 @@ separate versions of the admin site -- using the ``AdminSite`` instances
 respectively::
 
     # urls.py
-    from django.conf.urls import patterns, url, include
+    from django.conf.urls import patterns, include
     from myproject.admin import basic_site, advanced_site
 
     urlpatterns = patterns('',

docs/ref/contrib/comments/example.txt

@@ -141,7 +141,7 @@ enable it in your project's ``urls.py``:
 
 .. code-block:: python
 
-  from django.conf.urls import patterns, url, include
+  from django.conf.urls import patterns
   from django.contrib.comments.feeds import LatestCommentFeed
 
   urlpatterns = patterns('',

docs/ref/contrib/sitemaps.txt

@@ -256,7 +256,7 @@ Example
 
 Here's an example of a :doc:`URLconf </topics/http/urls>` using both::
 
-    from django.conf.urls import patterns, url, include
+    from django.conf.urls import patterns
     from django.contrib.sitemaps import FlatPageSitemap, GenericSitemap
     from blog.models import Entry
 

docs/ref/contrib/syndication.txt

@@ -77,7 +77,7 @@ latest five news items::
 To connect a URL to this feed, put an instance of the Feed object in
 your :doc:`URLconf </topics/http/urls>`. For example::
 
-    from django.conf.urls import patterns, url, include
+    from django.conf.urls import patterns
     from myproject.feeds import LatestEntriesFeed
 
     urlpatterns = patterns('',
@@ -321,7 +321,7 @@ Here's a full example::
 
 And the accompanying URLconf::
 
-    from django.conf.urls import patterns, url, include
+    from django.conf.urls import patterns
     from myproject.feeds import RssSiteNewsFeed, AtomSiteNewsFeed
 
     urlpatterns = patterns('',

docs/ref/models/instances.txt

@@ -601,7 +601,7 @@ pattern, it's possible to give a name to a pattern, and then reference the name
 rather than the view function. A named URL pattern is defined by replacing the
 pattern tuple by a call to the ``url`` function)::
 
-    from django.conf.urls import patterns, url, include
+    from django.conf.urls import url
 
     url(r'^people/(\d+)/$', 'blog_views.generic_detail', name='people_view'),