reconnect to redis after Spring forking

Change-Id: I161ae4964cb782839b9144b2bd7b726cde3479e8
Reviewed-on: https://gerrit.instructure.com/39534
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Brian Palmer <brianp@instructure.com>
QA-Review: Brian Palmer <brianp@instructure.com>