fix(mdns): define CONFIG_LWIP_IPV4 in mdns_private.h if it is not defined for IDF v5.0

Author: wqx6

components/mdns/examples/query_advertise/main/mdns_example_main.c

@@ -241,7 +241,7 @@ static void query_mdns_host(const char *host_name)
     struct esp_ip4_addr addr;
     addr.addr = 0;
 
-    esp_err_t err = mdns_query_a(host_name, 2000,  &addr);
+    esp_err_t err = mdns_query_a(host_name, 1000,  &addr);
     if (err) {
         if (err == ESP_ERR_NOT_FOUND) {
             ESP_LOGW(TAG, "%s: Host was not found!", esp_err_to_name(err));