Debug-log cookie login token regeneration

[ChristophWurst]

Follow-up to #33772 now that we have our first real-world feedback in #33919.

[nickvergessen]

Seems to confirm:

{"reqId":"4Q9o5Oo77xzHnOYfQIUH","level":2,"time":"2022-10-20T08:02:53+00:00","remoteAddr":"…","user":"--","app":"core","method":"GET","url":"/ocs/v2.php/apps/spreed/api/v1/chat/…","message":"Regenerating cookie login token for … after successful verification","userAgent":"Mozilla/5.0 …","version":"25.0.0.18","data":{"app":"core"}}
{"reqId":"o2QPBCrQftd2z0fxSojG","level":3,"time":"2022-10-20T08:02:53+00:00","remoteAddr":"…","user":"--","app":"core","method":"GET","url":"/ocs/v2.php/apps/notifications/api/v2/notifications","message":"Tried to log in … but could not verify token","userAgent":"Mozilla/5.0 …","version":"25.0.0.18","data":{"app":"core"}}
{"reqId":"kjn3gxMa96CHx5y1Cp6R","level":3,"time":"2022-10-20T08:02:53+00:00","remoteAddr":"…","user":"--","app":"core","method":"GET","url":"/csrftoken","message":"Tried to log in … but could not verify token","userAgent":"Mozilla/5.0 …","version":"25.0.0.18","data":{"app":"core"}}
{"reqId":"hDdnqKnVcQgoLq3Oof4i","level":3,"time":"2022-10-20T08:02:53+00:00","remoteAddr":"…","user":"--","app":"core","method":"GET","url":"/csrftoken","message":"Tried to log in … but could not verify token","userAgent":"Mozilla/5.0 …","version":"25.0.0.18","data":{"app":"core"}}
{"reqId":"suSulTRF6QiN7HdiLBr9","level":3,"time":"2022-10-20T08:02:53+00:00","remoteAddr":"…","user":"--","app":"core","method":"GET","url":"/csrftoken","message":"Tried to log in … but could not verify token","userAgent":"Mozilla/5.0 …","version":"25.0.0.18","data":{"app":"core"}}

5 parallel requests of the same user, the first one wins the others fail to renew

[ChristophWurst]

This didn't give clear insights. Closing.