Current connections is not a valid proxy for peer connectedness

[corverroos]

🐞 Bug Report

Description

We use current connections to check if we are connected to sufficient peers. This is however incorrect since connections break (especially relay connections) and are only re-established when the next message is sent. In most cases, the connection will be re-established and everything will be fine.

Proposed solution

Instead of "current connections", use "recent connections" (1 min should be fine). So keep a timestamp of last seen connection and if that is more than 1min, then count the peer as "not connected".