mdns: fix build issue with CONFIG_LWIP_IPV6 disabled

Author: mahavirj

components/mdns/idf_component.yml

@@ -1,4 +1,4 @@
-version: "1.0.5"
+version: "1.0.6"
 description: mDNS
 dependencies:
   idf:

components/mdns/mdns_networking_lwip.c

@@ -339,8 +339,12 @@ size_t _mdns_udp_pcb_write(mdns_if_t tcpip_if, mdns_ip_protocol_t ip_protocol, c
     memcpy((uint8_t *)pbt->payload, data, len);
 
     ip_addr_t ip_add_copy;
+#if CONFIG_LWIP_IPV6
     ip_add_copy.type = ip->type;
-    memcpy(&(ip_add_copy.u_addr),&(ip->u_addr),sizeof(ip_add_copy.u_addr));
+    memcpy(&(ip_add_copy.u_addr), &(ip->u_addr), sizeof(ip_add_copy.u_addr));
+#else
+    memcpy(&(ip_add_copy.addr), &(ip->u_addr), sizeof(ip_addr_copy.addr));
+#endif // CONFIG_LWIP_IPV6
 
     mdns_api_call_t msg = {
         .tcpip_if = tcpip_if,