Make it clear that you should not attempt to get the version before the
first handshake is complete.
Fixes #2893
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6015)
=head1 DESCRIPTION
SSL_get_version() returns the name of the protocol used for the
-connection B<ssl>.
+connection B<ssl>. It should only be called after the initial handshake has been
+completed. Prior to that the results returned from this function may be
+unreliable.
=head1 RETURN VALUES
=item unknown
-This indicates that no version has been set (no connection established).
+This indicates an unknown protocol version.
=back