public synchronized void checkForPluginsUpdates(boolean notificationsEnabled) throws Exception {
        final Optional<String> response = getResponse("available", getAvailablePluginsUpdateRequest());
        if (response.isPresent()) {
            processAvailablePluginsResponse(response.get(), notificationsEnabled);
        }
    }
Queries the igniterealtime.org server. It's response is expected to include a list of
plugins that are available on the server / for download.

@param notificationsEnabled true if admins will be notified when new updates are found.
@throws Exception if some error happens during the query.
xmppserver/src/main/java/org/jivesoftware/openfire/update/UpdateManager.java