Fix URL in e-mail notifications

owl.py

@@ -1697,7 +1697,7 @@ def send_notify_to_dest(post, topic, course, author, target, dest, reply_to):
     ]
     if post.modified:
         h.append(('Updated', post.modified.replace(microsecond=0).astimezone().strftime("%Y-%m-%d %H:%M:%S")))
-    h.append(('URL', url_for('topic_index', sident=course.ident, cident=course.ident, tident=topic.ident, student_uid=target_uid, _external=True, _scheme='https')))
+    h.append(('URL', url_for('topic_index', sident=course.sident, cident=course.ident, tident=topic.ident, student_uid=target_uid, _external=True, _scheme='https')))
     h.append(('Points', post.points if post.points is not None else '-'))
     head = "\n".join(["{:12} {}".format(p[0] + ':', p[1]) for p in h]) + "\n\n"
     body = post.comment or ""