fix shard category for delayed jobs

fixes CNVS-14415

Change-Id: I79ffedc430c00a73f32694b8ed8b8a25eb631099
Reviewed-on: https://gerrit.instructure.com/38828
Reviewed-by: Nick Cloward <ncloward@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>