tools: update to new Lua API

tools/level_editor/project.vala

@@ -181,7 +181,8 @@ public class Project
 				+ "\n"
 				+ "\n	-- Spawn camera"
 				+ "\n	local camera_unit = World.spawn_unit(GameBase.world, \"core/units/camera\")"
-				+ "\n	SceneGraph.set_local_position(Game.sg, camera_unit, Vector3(0, 6.5, -30))"
+				+ "\n	local camera_transform = SceneGraph.instance(Game.sg, camera_unit)"
+				+ "\n	SceneGraph.set_local_position(Game.sg, camera_transform, Vector3(0, 6.5, -30))"
 				+ "\n	GameBase.game_camera = camera_unit"
 				+ "\n	Game.camera = FPSCamera(GameBase.world, camera_unit)"
 				+ "\nend"