Use then instead of then_some when checking upnp_enabled to avoid useless UPnP query

[dknopik]

Issue Addressed

I noticed that Lighthouse sends to UPnP's multicast address 239.255.255.250 even though I passed --disable-upnp. After some investigation, I found out that libp2p_upnp's Behaviour::default immediately starts the search for the gateway. As we use bool::then_some to transform upnp_enabled into an Option<Behaviour>, we have to call Behaviour::default eagerly to pass it, triggering the search even if upnp_enabled is false.

Proposed Changes

Use bool::then instead, passing Behaviour::default as function reference so that it is called lazily (only when upnp_enabled is true).

Additional Info

In my opinion, starting the search immediately when Behaviour::default is invoked is bad design (as usually default only returns "some data"), so an alternative fix is to try and improve the API upstream.

[AgeManning]

Nice find. Thanks for the PR <3

[AgeManning]

@Mergifyio queue

[mergify]

queue

✅ The pull request has been merged automatically

The pull request has been merged automatically at a2ab26c