ssl_get_servername return null
#include <openssl/ssl.h>
long SSL_CTX_set_tlsext_servername_callback(SSL_CTX *ctx,
int (*cb)(SSL *, int *, void *));
long SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
const char *SSL_get_servername(const SSL *s, const int type);
int SSL_get_servername_type(const SSL *s);
JexFredO