mod_http_oauth2: Fire authentication events on login form For e.g. mod_audit_auth to use. A bit hacky because upon review many modules don't seem to handle the lack of an XMPP session in the event payload.

This module lets you block connections to any remote servers not on a
whitelist.

``` {.lua}
modules_enabled = {
    -- other modules --
    "s2s_whitelist",

}
s2s_whitelist = {
    "example.org",
}
```