fix update in migration

Change-Id: Id53a495deecc002aefdba1440b309cd19ca7cc77
Reviewed-on: https://gerrit.instructure.com/30034
Reviewed-by: Rob Orton <rob@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>