Unable to get token since migrating Wallabag database

Hi there,

First of all, thanks for the great work on this extension. Have been using it valuably for many years. Thanks!

I recently migrated my Wallabag database up to the latest version, which I should've done some time ago. This required a little hackery. Mostly deleting all rows from `wallabag_oauth2_auth_codes` and `wallabag_oauth2_refresh_tokens`, if I remember. Everything now seems to be ok, but now I have the problem that I can't get a token for the extension anymore:


I tried creating a new client and using those details. Also disabling 2FA which I had newly enabled. No luck.

When I try to get a token, I get the following in the Wallabag docker logs:

`172.22.0.255 - - [17/Dec/2020:11:03:10 +0100] "POST /oauth/v2/token HTTP/1.1" 500 4768 "-" "-"`

500 error. How can I get more information so I can diagnose the problem, please?

I hope someone can help.

Thanks in advance