don't send ruby object to statsd key

Change-Id: I7b81cc8017b24843f8c52fb0090374db8ee73691
Reviewed-on: https://gerrit.instructure.com/36650
Reviewed-by: Ben Chobot <bench@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>