fwup: Make the temporary set name shorter

And try to make the chance of reaching the ipset max name length limit
(31 chars) smaller. We actually hit the limit in practice.

src/plugins/fwup/main.c

@@ -102,7 +102,7 @@ static void replace_start(struct diff_addr_store *store) {
 	sanity(!set->tmp_name, "Replace already started\n");
 	struct mem_pool *tmp_pool = set->context->temp_pool;
 	// It is OK to allocate the data from the temporary memory pool. It's lifetime is at least the length of call to the plugin communication callback, and the whole set replacement happens there.
-	set->tmp_name = mem_pool_printf(tmp_pool, "%s-replace", set->name);
+	set->tmp_name = mem_pool_printf(tmp_pool, "%s-rep", set->name);
 	enqueue(set->context, set->context->user_data->queue, mem_pool_printf(tmp_pool, "create %s %s family %s hashsize %zu maxelem %zu\n", set->tmp_name, set->type->desc, set->type->family, set->hash_size, set->max_size));
 }