Support two-factor authentication (2FA) for non-Pro version

@Ludger Agreed completely. We’ve already seen the massive backlash that can occur over security incidents on personal cloud services with the recent NextCloud incident.

2FA is a golden standard for easy and reliable security. It should be available for free on all platforms and applications.

I also agree that features like LDAP, analytics, statistics and other “enterprise”-oriented features can be fairly justified for inclusion in the Pro version only. It is important for the Seafile company to be able to monetise their product, and most business customers are more than happy to pay for such features.