devel: truncate description of todolist overview

Some todolists have an elaborate description which takes up a lot of
space, limit these two 50 words.

templates/devel/index.html

@@ -140,7 +140,7 @@ <h3>Package Todo Lists</h3>
                         title="View todo list: {{ todo.name }}">{{ todo.name }}</a></td>
                 <td>{{ todo.created|date }}</td>
                 <td>{{ todo.creator.get_full_name }}</td>
-                <td class="wrap">{{ todo.description|urlize }}</td>
+                <td class="wrap">{{ todo.description|urlize|truncatewords:"50" }}</td>
                 <td>{{ todo.pkg_count }}</td>
                 <td>{{ todo.incomplete_count }}</td>
             </tr>