Fix swaybars with no defined output

sway/ipc-json.c

@@ -485,13 +485,13 @@ json_object *ipc_json_describe_bar_config(struct bar_config *bar) {
 	json_object_object_add(json, "colors", colors);
 
 	// Add outputs if defined
-	json_object *outputs = json_object_new_array();
 	if (bar->outputs && bar->outputs->length > 0) {
+		json_object *outputs = json_object_new_array();
 		for (int i = 0; i < bar->outputs->length; ++i) {
 			const char *name = bar->outputs->items[i];
 			json_object_array_add(outputs, json_object_new_string(name));
 		}
+		json_object_object_add(json, "outputs", outputs);
 	}
-	json_object_object_add(json, "outputs", outputs);
 	return json;
 }