mod_http_oauth2: Validate that informative URLs match the redirect URIs It is a bit shady to have the various URIs (URLs really) point to different hostnames. This may be quite stricter than required, but can always be relaxed later.

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",
}
```