mod_http_oauth2: Implement RFC 8628 Device Authorization Grant Meant for devices without easy access to a web browser, such as refrigerators and toasters, which definitely need to be running OAuth-enabled XMPP clients! Could be used for CLI tools that might have trouble running a http server needed for the authorization code flow.

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",
}
```