"aretefactid" is not defined error on db upgrade

[Robert Lyon]

On upgrade we sometimes get the error:

 [WAR] 66 (lib/db/upgrade.php:893) Undefined index: artefactid

This is due to trying to spot the array key 'artefactid' whn it's value is null

But if 'artefactid' is not set at all we get the error.

Need to use array_key_exists() instead of is_null()

As the upgrade will still complete I will mark as medium bug

[Robert Lyon (robertl-9)]

https://reviews.mahara.org/#/c/9524/

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/9524
Committed: https://git.mahara.org/mahara/mahara/commit/ddd0ac8a2820495cf99465b70932eccd4e807cb4
Submitter: Cecilia Vela Gurovic (<email address hidden>)
Branch: master

commit ddd0ac8a2820495cf99465b70932eccd4e807cb4
Author: Robert Lyon <email address hidden>
Date: Thu Feb 7 08:49:36 2019 +1300

Bug 1814954: Getting "Undefined index: artefactid" on upgrade

Due to checking for a null array vaue incorrectly

behatnotneeded

Change-Id: Iac2d98878f9baea098af6661d08a4d2dcc6be30b
Signed-off-by: Robert Lyon <email address hidden>