peer: only return a channel snapshot if the channel can route
peer: only return a channel snapshot if the channel can route

In this commit, we fix a slight miscalculation within the GetInfo call.
Before this commit, we would list any channel that the peer knew of as
active, instead of those which are, well, actually *active*. We fix
this by skipping any channels that we don’t have the remote revocation
for.

aakselrod/lnd,LightningNetwork/lnd,LightningNetwork/lnd,aakselrod/lnd