mod_http_oauth2: Allow loopback IP literals in redirect URIs Previously only exactly "http://localhost" was allowed, but RFC 8252 seems to recommend both ::1 and 127.0.0.1 be allowed.

This module blocks configured queries that change server state.

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

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