mod_client_management: Report on longest lived token when grant does not expire E.g. for mod_http_oauth2 where by default the grant itself is unlimited, while refresh tokens are issued with one week lifetime, but are renewed with each use.

This module blocks configured queries that change server state.

E.g. to make vCard storage read-only:

``` lua
readonly_stores = {
	vcard = { "vcard-temp", "vCard" };
}
```