Creating a 2.2 assignment online audio recording activity generates a strict standards warning

If you edit a course and create an "online audio recording" activity you will see the following message.

Strict Standards: Declaration of assignment_onlineaudio::send_file() should be compatible with that of assignment_base::send_file() in /home/andrew/Desktop/code/moodle/int/master/mod/assignment/type/onlineaudio/assignment.class.php on line 621