mod_http_oauth2: Allow revoking a token without OAuth client credentials If you have a valid token, and you're not supposed to have it, revoking it seems the most responsible thing to do with it, so it should be allowed, while if you are supposed to have it, you should also be allowed to revoke it.

This module blocks configured queries that change server state.

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

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