Corrected description of list_display being a list in tutorial 7.

AUTHORS

@@ -128,6 +128,7 @@ answer newbie questions, and generally made Django that much better:
     av0000@mail.ru
     Axel Haustant <noirbizarre@gmail.com>
     Aymeric Augustin <aymeric.augustin@m4x.org>
+    Aleksander Milinkevich <milinsoft@gmail.com>
     Bahadır Kandemir <bahadir@pardus.org.tr>
     Baishampayan Ghose
     Baptiste Mispelon <bmispelon@gmail.com>

docs/intro/tutorial07.txt

@@ -199,7 +199,7 @@ Here's what it looks like at this point:
 By default, Django displays the ``str()`` of each object. But sometimes it'd be
 more helpful if we could display individual fields. To do that, use the
 :attr:`~django.contrib.admin.ModelAdmin.list_display` admin option, which is a
-tuple of field names to display, as columns, on the change list page for the
+list of field names to display, as columns, on the change list page for the
 object:
 
 .. code-block:: python