smb: Fixed Windows autoconf builds following commit eb88d778e7

As Windows based autoconf builds don't yet define USE_WIN32_CRYPTO
either explicitly through --enable-win32-cypto or automatically on
_WIN32 based platforms, subsequent builds broke with the following
error message:

"Can't compile NTLM support without a crypto library."

lib/curl_ntlm_core.c

@@ -31,6 +31,8 @@
  * http://www.innovation.ch/java/ntlm.html
  */
 
+#if !defined(USE_WINDOWS_SSPI) || defined(USE_WIN32_CRYPTO)
+
 #ifdef USE_SSLEAY
 
 #  ifdef USE_OPENSSL
@@ -734,4 +736,6 @@ CURLcode  Curl_ntlm_core_mk_lmv2_resp(unsigned char *ntlmv2hash,
 
 #endif /* USE_NTRESPONSES */
 
+#endif /* !USE_WINDOWS_SSPI || USE_WIN32_CRYPTO */
+
 #endif /* USE_NTLM */