Wrong SSL version in DTLS1_BAD_VER ClientHello

Since commit 741c9959

 ("DTLS revision."), we put the wrong protocol
version into our ClientHello for DTLS1_BAD_VER. The old DTLS
code which used ssl->version was replaced by the more generic SSL3 code
which uses ssl->client_version. The Cisco ASA no longer likes our
ClientHello.

RT#3711

Reviewed-by: Rich Salz <rsalz@openssl.org>