fix page_view after_initialize callback for rails 3

Change-Id: If87f098435b873074295586a112734a7ce6087a1
Reviewed-on: https://gerrit.instructure.com/29038
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: James Williams  <jamesw@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>