sched: scheduler_notify_networkstatus_changed() calls select_scheduler() without the new consensus

select_scheduler() is called when a new consensus arrives with scheduler_notify_networkstatus_changed() but never takes the new consensus for which at that point it is not yet set as the global consensus.

It needs to use new_c.

This is not good because of that, we can't change anything with the consensus at runtime.........

Thanks to Roger for finding this out here: https://oniongit.eu/dgoulet/tor/merge_requests/17#note_2153