vpython: don't mess with logging in -dev mode.
vpython: don't mess with logging in -dev mode.

BUG=None
TEST=None
R=iannucci@chromium.org

Review-Url: https://codereview.chromium.org/2836383003

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