swarming: fix spell
swarming: fix spell

This is for
https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/2089165/8/appengine/swarming/server/bot_management_test.py#475

Change-Id: I5858b09655cebc8ca5b949a2b16818ce978e959a
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/2097764
Reviewed-by: Ye Kuang <1cd89f22f3967fc3dcb883b53940be4b98ec483f@google.com>
Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Auto-Submit: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py