Fix NPE for Point convertion to Pos

BauSystem_Main/src/de/steamwar/bausystem/features/script/lua/libs/LuaLib.java

@@ -71,6 +71,7 @@ public interface LuaLib {
     }
 
     default LuaTable toPos(Point point) {
+        if (point == null) return LuaTable.tableOf();
         return LuaValue.tableOf(new LuaValue[] {
                 LuaValue.valueOf("x"), LuaValue.valueOf(point.getX()),
                 LuaValue.valueOf("y"), LuaValue.valueOf(point.getY()),