Artefact annotation blocktype js not using correct path when in cleanurls mode

[Robert Lyon]

The call to the related json.php file tries to traverse the relative path rather than use the explicit path with config.wwwroot as base of path

[Robert Lyon (robertl-9)]

https://reviews.mahara.org/#/c/8333/

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/8333
Committed: https://git.mahara.org/mahara/mahara/commit/6b31906f59d22294e6b2ff66158cc7d869fb78d9
Submitter: Robert Lyon (<email address hidden>)
Branch: master

commit 6b31906f59d22294e6b2ff66158cc7d869fb78d9
Author: Robert Lyon <email address hidden>
Date: Fri Dec 8 12:56:25 2017 +1300

Bug 1737059: Artefact annotation blocktype js not using correct path

When in cleanurls mode.

It tries to traverse the relative path rather than use the
config.wwwroot as base of path

Also we don't need the check if limit/offset is false as they are fetched
by function that returns null rather than false now

behatnotneeded

Change-Id: Iad206788c31b8fbfd10d5689e335c96b48bf7112
Signed-off-by: Robert Lyon <email address hidden>