Fixed NTLM on curl-config --features with GnuTLS

configure.ac

@@ -2508,7 +2508,7 @@ fi
 if test "x$USE_WINDOWS_SSPI" = "x1"; then
   SUPPORT_FEATURES="$SUPPORT_FEATURES SSPI"
 fi
-if test "x$USE_SSLEAY" = "x1" -o "x$USE_WINDOWS_SSPI" = "x1" -o "x$USE_GNUTLS" = "x1"; then
+if test "x$USE_SSLEAY" = "x1" -o "x$USE_WINDOWS_SSPI" = "x1" -o "x$GNUTLS_ENABLED" = "x1"; then
   SUPPORT_FEATURES="$SUPPORT_FEATURES NTLM"
 fi