SNIExtension was previously marshalling both ip addresses and empty
strings, which are not allowed. See RFC 6066, Section 3.
All of the utls specific testdata replays needed to be rebuilt to
properly accomodate this change since they had previously been including
empty server name extension values
Addresses https://github.com/refraction-networking/utls/issues/96
I tested all fingerprints and confirmed that Chrome and Firefox are
working as intended.
Android fingerprints were grossly unpopular, which could a result of
incorrect merge, but either way we'll remove them for now.
