The usual recommended upgrade is to use some add-on tool like NGINX.
I do not know, but there may be good reasons not to tinker with jetty.
This very old thread explores some of the options. From what I can make out. jetty is not itself very helpful e.g. does not support certs?
For what its worth, I miss the simple password of OH1, but we are where we are, and that probably gave a false sense of security.