修复重启后 创建dms文件夹出错问题
重启后 会创建dms文件夹，如果已经存在该文件夹会报错，错误如下： 2022-05-26 14:43:52.009 [ERROR] [Docker Security Env] security/security_env.go:81 fail to set dms directory, err: [mkdir /dms: file exists] 2022-05-26 14:43:52.019 [ERROR] [Docker MANAGER] module/manager.go:33 fail to init directory: mkdir /dms: file exists 2022-05-26 14:43:52.028 [ERROR] [Docker MANAGER] dockervm/main.go:46 Err in creating docker manager: mkdir /dms: file exists 修改方法：判断dms文件夹是否存在