[1.5.x] Fixed #21440 -- Typo #2 in topics/http/shortcuts.txt

Thanks alasdair.

Backport of d011714 from master

docs/topics/http/shortcuts.txt

@@ -152,7 +152,7 @@ This example is equivalent to::
 
     def my_view(request):
         # View code here...
-        t = loader.get_template('myapp/template.html')
+        t = loader.get_template('myapp/index.html')
         c = Context({'foo': 'bar'})
         return HttpResponse(t.render(c),
             content_type="application/xhtml+xml")