Investigate using of TLSv1_method instead of SSLv23_method

tortls.c

#if 0
  /* Tell OpenSSL to only use TLS1.  This may have subtly different results
   * from SSLv23_method() with SSLv2 and SSLv3 disabled, so we need to do some
   * investigation before we consider adjusting it. It should be compatible
   * with existing Tors. */
  if (!(result->ctx = SSL_CTX_new(TLSv1_method())))
    goto error;
#endif

s23_*.c files of OpenSSL code doesn't seems like many eyes will looking at.