fix sad sad 'available' typo

fixes CNVS-15533

test plan
- it should be spelled right :thumbsup:

Change-Id: I9d4d769c4d09301a102befd644bd54e7368b4bb3
Reviewed-on: https://gerrit.instructure.com/41117
Reviewed-by: Cameron Sutter <csutter@instructure.com>
QA-Review: Anna Koalenz <akoalenz@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Liz Abinante <labinante@instructure.com>