Fix Win -> Windows when triggering tasks.
Fix Win -> Windows when triggering tasks.

It was an error in commit b39e8cf0, 'Win' has never been used.

R=csharp@chromium.org
BUG=

Review URL: https://codereview.appspot.com/79630044

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