Removed a colon that was rendering the bullet-point list below it as code in docs/admin.txt.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8066 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/admin.txt

@@ -511,7 +511,7 @@ specifying them in a ``ModelAdmin.inlines`` attribute::
             BookInline,
         ]
 
-Django provides two subclasses of ``InlineModelAdmin`` and they are::
+Django provides two subclasses of ``InlineModelAdmin`` and they are:
 
     * ``TabularInline``
     * ``StackedInline``