[logdog] Don't promote dev upload.
[logdog] Don't promote dev upload.

The Makefile forgot to set the "--no-promote" flag when uploading the
dev static instance.

TBR=hinoka@chromium.org
BUG=None
TEST=None

Review-Url: https://codereview.chromium.org/2990133002

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