getting quotausedpercent can cause 'divide by zero' error

[Robert Lyon]

If we set a user's quota to 0 it throws an error:

[WAR] bb (admin/users/edit.php:356) Division by zero
Call stack (most recent first):

    log_message("Division by zero", 8, true, true, "/home/robertl/htdocs/mahara-devel/mahara/htdocs/ad...", 356) at /home/robertl/htdocs/mahara-devel/mahara/htdocs/lib/errors.php:439
    error(2, "Division by zero", "/home/robertl/htdocs/mahara-devel/mahara/htdocs/ad...", 356, array(size 7)) at /home/robertl/htdocs/mahara-devel/mahara/htdocs/admin/users/edit.php:356

Normally we wouldn't be setting a user's quota to 0 - but for automated tests this can make sense.

So it is useful to fix for that reason.

Noticed when running webservices phpunit tests

[Mahara Bot (dev-mahara)]

Patch for "master" branch: https://reviews.mahara.org/3986

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/3986
Committed: http://gitorious.org/mahara/mahara/commit/f6ff1d28aa11bf78932aa08dc84d7eb027f423ad
Submitter: Son Nguyen (<email address hidden>)
Branch: master

commit f6ff1d28aa11bf78932aa08dc84d7eb027f423ad
Author: Robert Lyon <email address hidden>
Date: Tue Nov 18 11:43:44 2014 +1300

Quota percent 'divide by zero' error (Bug 1393584)

Change-Id: I252c5f763ccc83d846f5dcc7fd086d723b31e2e6
Signed-off-by: Robert Lyon <email address hidden>