code: def ensure_one_subscription():
      
      cursor = connection.cursor()
      cursor.execute("UPDATE subscription_subscription SET active = False \
                      WHERE id NOT IN \
                     (SELECT MAX(id) as id FROM \
                      subscription_subscription GROUP BY to_addr)")
      affected = cursor.rowcount
      vumi_fire_metric.delay(
          metric="subscription.duplicates", value=affected, agg="last")
      return affected
docs: Fixes issues caused by upstream failures
      that lead to users having multiple active subscriptions
      Runs daily