Allocate a port on prometheus wiki

https://github.com/prometheus/prometheus/wiki/Default-port-allocations

In that wiki there is a list off port allactions for exporters.

This is an extract of the prometheus documentation

A user may have many exporters and Prometheus components on the same machine, so to make that easier each has a unique port number.

https://github.com/prometheus/prometheus/wiki/Default-port-allocations is where we track them, this is publicly editable.

Feel free to grab the next free port number when developing your exporter, preferably before publicly announcing it. If you’re not ready to release yet, putting your username and WIP is fine.

This is a registry to make our users’ lives a little easier, not a commitment to develop particular exporters. For exporters for internal applications we recommend using ports outside of the range of default port allocations.

lndmon is using 9092 by default. It might be good to choose something else and publicly announce it in that wiki

Start with the Prometheus Default port allocations wiki and inspect where lndmon's default port 9092 is configured. Choose an available allocation, update the default and the wiki entry, then verify that the documented and runtime defaults agree.