Doesn't send list of allowed issuers when TLS client authentication is enabled

[blackbird1999]

The
inline SSLServer::SSLServer(const char *cert_path, const char *private_key_path,
const char *client_ca_cert_file_path,
const char *client_ca_cert_dir_path,
const char *private_key_password);
should include a call to SSL_CTX_set_client_CA_list when client_ca_cert_file_path is provided so that the server will send the client the list of issuer distinguished names that the server will accept for TSL client/certificate authentication.

Something like
if (client_ca_cert_file_path)
{
SSL_CTX_set_client_CA_list(ctx_, SSL_load_client_CA_file(client_ca_cert_file_path));
}
after the call to SSL_CTX_load_verify_locations().

It should also do it for the client_ca_cert_dir_path option, but that's more complicated and annoying.

[Xxproner]

STACK_OF(X509_NAME) *SSL_load_client_CA_file(const char *file); // dir annoying, I agreed
void SSL_CTX_set_client_CA_list(SSL_CTX *ctx, STACK_OF(X509_NAME) *list);
int SSL_CTX_load_verify_locations(SSL_CTX *ctx, const char *CAfile,
                                      const char *CApath);

Provide these funcs, and it works. As opessl documented, *_load_verify_locations() should be called after *_set_client_CA_list()