Use new signature for XID param callback

src/server.c

@@ -1312,8 +1312,7 @@ error_sock_resend:
 }
 
 static int handle_xid_param(enum patty_ax25_frame_xid_param_type type,
-                            size_t len,
-                            uint8_t *data,
+                            uint32_t value,
                             void *ctx) {
     return 0;
 }