Vantage6: 2FA can be circumvented with hacked email access

vantage6 is an open-source infrastructure for privacy preserving analysis. Prior to version 5.0.0, if an attacker hacks into a vantage6 user's email account, they can 1) reset the password via email and then 2) reset the 2FA token via email. This way they reduce 2FA to 1FA (email access). Note that most email providers require 2FA to access email, so this issue is not very likely to cause issues. Version 5.0.0 fixes the issue. No known workarounds are available.