check for tld_strerror

configure.ac

@@ -977,7 +977,7 @@ case "$LIBIDN" in
        if test "x$idn" = "xyes"; then
          curl_idn_msg="enabled"
          dnl different versions of libidn have different setups of these:
-         AC_CHECK_FUNCS( idn_free idna_strerror )
+         AC_CHECK_FUNCS( idn_free idna_strerror tld_strerror)
          AC_CHECK_HEADERS( idn-free.h )
        fi