public String getNotificationMessage() {
        return LocaleUtils.getLocalizedString("update.notification-message");
    }
Returns the message to send to admins when new updates are available. When sending
this message information about the new updates avaiable will be appended.

@return the message to send to admins when new updates are available.
xmppserver/src/main/java/org/jivesoftware/openfire/update/UpdateManager.java