[task_dispensers/combinatory_test] fix missing template field"

This regression was introduced by #917

inginious/frontend/task_dispensers/combinatory_test.py

@@ -50,8 +50,10 @@ def render_edit(self, template_helper, course, task_data):
 
     def render(self, template_helper, course, tasks_data, tag_list, username):
         """ Returns the formatted task list"""
+        accessibilities = course.get_task_dispenser().get_accessibilities(self._task_list_func(), [username])
         return template_helper.render("task_dispensers/toc.html", course=course, tasks=self._task_list_func(),
-                                      tasks_data=tasks_data, tag_filter_list=tag_list, sections=self._toc)
+                                      tasks_data=tasks_data, tag_filter_list=tag_list, sections=self._toc,
+                                      accessibilities=accessibilities)
 
     def check_dispenser_data(self, dispenser_data):
         """ Checks the dispenser data as formatted by the form from render_edit function """