Adman (the hoster) have not provided an ETA for native v6 on bugry yet, so we
establish a public v6 connection through nevsky for now.
In traffic flows going West->East the overhead is minimal (a few ms), though I
guess it might be worse if you're in the middle (Yekaterinburg or something).
The prefix was chosen by the bugry public v4 address encoded in hex, and
appended to the nevsky prefix.
Change-Id: I133622c17bd02eade0a6febc6bdf97f403fed14c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12974
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>