fix empty revisions display when restoring a page

test plan:
 * rename a wiki page several times
 * navigate to the revision history for the page
 * restore to a version with a different page name
 - the page should refresh, showing the newly restored name

fixes CNVS-13845

Change-Id: I56df4de17f25393e3d2ce585c777ef3d5a483e51
Reviewed-on: https://gerrit.instructure.com/37470
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Clare Strong <clare@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>