RPKI test does not handle IPv6-mapped IPv4 correctly

[mxsasha]

With 5bb8e74 this is no longer seen as an IPv6 name server for the IPv6 test, but the RPKI test should also unwrap this. Or at least do something better than this. #146 / #655 for previous work.

[WKobes]

Two real-life examples:

https://batch.internet.nl/mail/haarlemmermeer.nl/4250012/#control-panel-31
https://batch.internet.nl/site/www.sitearchief.nl/2948352/#control-panel-35

[baknu]

@mxsasha: Should we make a remark in de test explanation on this? And if so, do you have a suggestion?

In the explanation of the IPv6 test the following is stated::

'IPv4-mapped IPv6 addresses' (RFC 4291, beginning with ::ffff:) will fail in this subtest, as they do not provide IPv6 connectivity.

[mxsasha]

@mxsasha: Should we make a remark in de test explanation on this? And if so, do you have a suggestion?

Don't think so. It's more of a different notation of an IPv4 address - there is no ambiguity in which address is meant in terms of routing.