Stop trying to get integrity level on XP, it doesn't exist.
Stop trying to get integrity level on XP, it doesn't exist.

The XP bots have their log spammed with:
  "ERROR GetTokenInformation() returned size 0"

It's not useful nor necessary.

R=vadimsh@chromium.org
BUG=

Review URL: https://codereview.appspot.com/184090043

luci/luci-py,madecoste/swarming,pombreda/swarming,madecoste/swarming,pombreda/swarming,pombreda/swarming,luci/luci-py,madecoste/swarming,luci/luci-py,luci/luci-py,madecoste/swarming,pombreda/swarming