fix bug

fix bug: old permission is root, need to change when start

fix bug: old permission is root, need to change when start

feat: 启动时增加目录的权限检测 fixed #412

Merge pull request #388 from talebook/dependabot/npm_and_yarn/app/tar…

…-6.2.1

Bump tar from 6.1.11 to 6.2.1 in /app

修正书籍导入的BUG：界面统计不对，多次导入时报错等

优化启动提示

优化导入页面，增加Tab分类 fix #361

优化BOOKDOWNLOAD的代码，使用tornado的文件处理逻辑，支持304等功能

删掉锁