package/libcurl: fix build w/ threads + c-ares

Fixes:
https://autobuild.buildroot.net/results/680b825b93989e6aef247593c198094a6ed916f7/

Since curl 8.14.0 with commit d364f1347f05 ("configure: catch asking for
double resolver without https-rr"), configure errors out when
--enabled-threaded-resolver is used together with --enable-ares (unless the
experimental HTTPS-RR support is enabled), so disable the threaded resolver
when c-ares is enabled.

https://github.com/curl/curl/commit/d364f1347f05c53eea5d25a15b4ad8a62ecc85b8

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/libcurl/libcurl.mk

@@ -36,7 +36,9 @@ LIBCURL_CONF_OPTS = \
 # https://nvd.nist.gov/vuln/detail/CVE-2024-32928
 LIBCURL_IGNORE_CVES += CVE-2024-32928
 
-ifeq ($(BR2_TOOLCHAIN_HAS_THREADS),y)
+# threaded resolver cannot be used with c-ares
+# https://github.com/curl/curl/commit/d364f1347f05c53eea5d25a15b4ad8a62ecc85b8
+ifeq ($(BR2_TOOLCHAIN_HAS_THREADS)x$(BR2_PACKAGE_C_ARES)),yx)
 LIBCURL_CONF_OPTS += --enable-threaded-resolver
 else
 LIBCURL_CONF_OPTS += --disable-threaded-resolver