private HttpRoutePlanner getRoutePlanner() {
        if (isUsingProxy()) {
            return new DefaultProxyRoutePlanner(new HttpHost(getProxyHost(), getProxyPort()));
        } else {
            return new DefaultRoutePlanner(null);
        }
    }
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