change sys.config to optional
change sys.config to optional

zhuxiangkui/erl_tool,wcy123/erl_tool,zhangchaoeasemob/erl_tool,zhangchaoeasemob/erl_tool,zhuxiangkui/erl_tool,zhangchaoeasemob/erl_tool,zhuxiangkui/erl_tool,wcy123/erl_tool,zhangchaoeasemob/erl_tool,wcy123/erl_tool,zhuxiangkui/erl_tool,zhuxiangkui/erl_tool,wcy123/erl_tool,zhangchaoeasemob/erl_tool,wcy123/erl_tool