Email MFA codes sometimes don't work

[t-aleksander]

Describe the bug
A lot of times the first code for MFA login i get in my inbox doesn't work. I get a message that "Submitted code is invalid." with a status code 401.

To Reproduce
Steps to reproduce the behavior:

1. Try to login with email MFA enabled
2. When asked, input the received code
3. The first code doesn't work. If it works, try it again

This issue may also be sometimes observed when performing the unit tests. One of the tests testing the email mfa failed today during the first run, but succeeded during the second one and i assume this is the cause.

Expected behavior
Every code should work.

[t-aleksander]

fixed in #714