fix js error for account groups page

fixes CNVS-13600

test plan:
- visit the account groups page
- it should not throw an error and should work

Change-Id: I5a9a6ce10240b5e1650b49a4cf7566a339174229
Reviewed-on: https://gerrit.instructure.com/36392
Reviewed-by: Braden Anderson <braden@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>
Product-Review: Braden Anderson <braden@instructure.com>