Corrects bug (uncovered by newer versions of CGI.pm after version 3.29 and before 3.42) which defaultedstudents to "guests" in the permission popup menu used for editing the student record. It showed uponly for student because there default value was 0 -- which can be treated ambiguously -- as opposed to2 or 10 which is not.
Adding the override switch forces the default value generated in the perl code to override other default
values for the popupmenu and provides the expected behavior.
This should fix the bug where students were mysteriously reassigned as guests and lost their "submit answer" buttons.
sites with older versions of CGI.pm will not have observed this problem.