MT#61856 sdp.c: `sdp_out_add_media_connection()` add assert

Add assert for the case when the execution sequence:
`get_any_interface_address()` -> `get_interface_address()`
still returns NULL.

If to dereference the `local_intf` later without checking it,
then it's definitely a crash.

Change-Id: Idc8557dd5352a6a421ca4056ef1ebd822be5fe08

daemon/sdp.c

@@ -3252,6 +3252,7 @@ static void sdp_out_add_media_connection(GString *out, struct call_media *media,
 				ifa = rtp_ps->selected_sfd->local_intf;
 			else
 				ifa = get_any_interface_address(rtp_ps->media->logical_intf, rtp_ps->media->desired_family);
+			assert(ifa != NULL);
 			ifa_addr = &ifa->spec->local_address;
 			media_conn_address_type = ifa_addr->addr.family->rfc_name;
 			media_conn_address = ifa_addr->addr.family->unspec_string;