on whitby, cgit runs as the gerrit user to get access to serving
gerrit's repositories directly.
on other machines (e.g. sanduny) this isn't necessary, as we have a
world-readable depot replica.
Change-Id: Ibf7e7cc08e5909e0fa182e561ab0cb472188edcb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5932
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
fcfd097e65