curl_setup.h: undef freeaddrinfo in c-ares block to fix build

Fixes warnings 78c25c854a added.

lib/curl_setup.h

@@ -527,6 +527,7 @@
 #  define CURLRES_ARES
 /* now undef the stock libc functions just to avoid them being used */
 #  undef HAVE_GETADDRINFO
+#  undef HAVE_FREEADDRINFO
 #  undef HAVE_GETHOSTBYNAME
 #elif defined(USE_THREADS_POSIX) || defined(USE_THREADS_WIN32)
 #  define CURLRES_ASYNCH