Client id of site owner doesn't get cached if revenue sharing is disabled.

The client id of the site owner doesn't get cached.

if (!$revenue) {
    // If not enabled, cache the site wide client ID
    return $site_client;
}

Should be something like:

if (!$revenue) {
    // If not enabled, cache the site wide client ID
    $client = $site_client;
    return $client;
}