When the userinfo claims store in the usercache is found to be expired,
do not return an error but ignore the cached entry and force a
re-verification of the access token (either via parsing the JWT again or
via a UserInfo lookup).
This is required for setups with non-JWT access tokes where the expiry
date set in the cached claims does not reflect the actual token expiry,
but just the CacheTTL.
Fixes: #1493
6dde2839df