tcptls.c: fix build with OpenSSL 4

tcptls.c: fix build with OpenSSL 4

tcptls.c: In function '__ssl_setup':
tcptls.c:417:52: error: implicit declaration of function 'SSLv3_client_method';
 did you mean 'SSLv23_client_method'? [-Wimplicit-function-declaration]
  417 |                         cfg->ssl_ctx = SSL_CTX_new(SSLv3_client_method());

SSLv3_client_method was removed from OpenSSL 4.0.0:
https://github.com/openssl/openssl/blob/openssl-4.0.0/doc/man7/ossl-removed-api.pod?plain=1#L440

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Resolves: #1952