promote read-only disablement log from net_plugin to warn level

[spoonincode]

Change Description

The message that net_plugin was disabling incoming connections was only info level. This seems a serious enough message to promote to warning level so it's easier to spot because some users have been caught by it. Plus, I've made it so if incoming connection are already disabled (p2p-listen-endpoint is empty) then there is no warning, so it's not necessarily going to be warning spam.

This does change the behavior so that instead of setting p2p-max-nodes-per-host to 0 the entire listening socket is disabled instead. I think that's fine as it's "more off".

Consensus Changes

• Consensus Changes

API Changes

• API Changes

Documentation Additions

• Documentation Additions

[heifner]

This looks like a better way to do this and I agree this should be a warning. However, in the description it is not correct to say info is not reported, as info is now the default since #7792

[spoonincode]

yeah not sure why I mixed that up; I even tried it and didn't think I saw it printed as info but yep it's there