[logdog] Fix unauthenticated redirection
[logdog] Fix unauthenticated redirection

Bug: 918866
Change-Id: I8b5fb39bae69dece511c5915c22f10554f0940c6
Reviewed-on: https://chromium-review.googlesource.com/c/1395973
Reviewed-by: Quinten Yearsley <747cf52e0cef2e3e9371802a2d344b6c87126a4b@chromium.org>
Commit-Queue: Ryan Tseng <2190fe9a39b4920ec7bd59c848ec5cccd163056f@chromium.org>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go