install时数据库出错 panic: Member.Add => 密码不能为空且必须在6-50个字符之间 #57

请按照一下格式提交issue，谢谢！

1. 你当前使用的是哪个版本的 BookStack?
   2.0
2. 你当前使用的是什么操作系统?
   debian windows10 都可以重现
3. 你是如何操作的？
   ./BookStack install
4. 你期望得到什么结果?
   安装成功的提示
5. 当前遇到的是什么结果?
   安装不成功，部分日志：
   ‘’‘
   [ORM]2019/08/15 03:48:53 -[Queries/default] - [ OK / db.Query / 0.4ms] - [SELECT T0.member_id, T0.account, T0.nickname, T0.password, T0.auth_method, T0.description, T0.email, T0.phone, T0.avatar, T0.role, T0.status, T0.create_time, T0.create_at, T0.last_login_time, T0.wxpay, T0.alipay FROM md_members T0 WHERE T0.account = ? ORDER BY T0.member_id DESC LIMIT 1] - admin
   panic: Member.Add => 密码不能为空且必须在6-50个字符之间

goroutine 1 [running]:
github.com/TruthHun/BookStack/commands.initialization()
D:/workspace/golang/src/github.com/TruthHun/BookStack/commands/install.go:63 +0x792
github.com/TruthHun/BookStack/commands.Install()
D:/workspace/golang/src/github.com/TruthHun/BookStack/commands/install.go:23 +0xae
github.com/TruthHun/BookStack/commands.RegisterCommand()
D:/workspace/golang/src/github.com/TruthHun/BookStack/commands/command.go:124 +0x198
main.main()
D:/workspace/golang/src/github.com/TruthHun/BookStack/main.go:24 +0xe5

’‘’