don't traverse disabled blocks in random mode

fixes #167

brickrail-gui/layout/route/layout_node.gd

@@ -63,6 +63,10 @@ func calculate_routes(reversing_behavior, train_id=null):
 		current_node.collect_edges()
 		for neighbour_id in current_node.edges:
 			var edge = current_node.edges[neighbour_id]
+
+			if LayoutInfo.nodes[neighbour_id].type=="block":
+				if LayoutInfo.nodes[neighbour_id].obj.disable_train:
+					continue
 
 			if train_id != null:
 				var edge_locked = edge.get_locked()

brickrail-gui/layout/train/layout_train.gd

@@ -129,7 +129,7 @@ func is_end_of_leg():
 	return route.get_current_leg().is_complete()
 
 func _on_LayoutInfo_random_targets_set(_random_targets):
-	if LayoutInfo.random_targets and route==null and random_targets:
+	if LayoutInfo.random_targets and route==null and random_targets and not block.disable_train:
 		find_random_route(false)
 
 func update_control_ble_train():
@@ -227,6 +227,8 @@ func get_all_valid_routes(no_locked=true, target_facing=null):
 			continue
 		if not LayoutInfo.nodes[node_id].obj.can_stop:
 			continue
+		if LayoutInfo.nodes[node_id].obj.disable_train:
+			continue
 		if target_facing != null and target_facing != LayoutInfo.nodes[node_id].facing:
 			continue
 		if not LayoutInfo.nodes[node_id].obj.random_target: