Disable address validation for throughput test

Disable address validation for throughput test

The multiplexing test using quiche as a client seems to get confused
when server address validation is enabled.  specifically it writes the
wrong keys into its keylog file, causing the test to fail when tshark
can't decode the tls connection that is established.  Fix it by
disabling address validation for the multiplexing/transfer test

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/26198)