Downgrade "Overwritting ContentEntry" from error to warning.
Downgrade "Overwritting ContentEntry" from error to warning.

We see it's happening often but it's not worth sending error reports for these.
I'll look at handling this a bit later.

R=vadimsh@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1836423003

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