Cluster.ConnectionManager.handle_info({:leadership_change, ...}) used
a cond on the (became_leader, node, connection_started) triple. Split
into handle_leadership_change/3 with three clauses:
- became_leader=true, us=true, not already started → start APRS-IS
- became_leader=false, us=true, already started → stop APRS-IS
- everything else → no-op
Makes the three state transitions visible in the function heads and
eliminates one more cond from the codebase.
Graham McIntire
a85f74ec3f