No v3 keys allowed

[Robert J. Hansen]

> How can I create a v4 key?

v3 keys are the kind generated by PGP 2.6.2, dating from the early
1990s.  You certainly created a v4 key.  Another strong hint comes from
your key fingerprint, which is a v4-style 160-bit hash.  v3 keys
overwhelmingly used 128-bit hashes.

My suspicion is that keyserver.pgp.com doesn't support elliptical curve
keys, and when it throws an error it has half-assed error handling that
assumes "if I couldn't import the key it must've been a v3 key."