don't run empty update_all in touch_all
don't run empty update_all in touch_all

Change-Id: Ic336e52612183ebc5787fd8e3bd45c494f296ce5
Reviewed-on: https://gerrit.instructure.com/89724
Tested-by: Jenkins
Reviewed-by: Jeremy Stanley <b3f594e10a9edcf5413cf1190121d45078c62290@instructure.com>
Product-Review: James Williams  <3a5f4ed991dbfa5c9ef76ad729d240ca12f62180@instructure.com>
QA-Review: James Williams  <3a5f4ed991dbfa5c9ef76ad729d240ca12f62180@instructure.com>

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