rpc: don't show pending channel in the ListChannels RPC call
rpc: don't show pending channel in the ListChannels RPC call

With the concept of open/pending channels on disk, we now will no
longer show channels under ListChannels that are still pending. This
fixes a slight existing bug wherein channels that weren’t yet open
would be listed in this RPC call since we write to disk immediately
after broadcasting the funding transaction.

AndrewSamokhvalov/lnd,aakselrod/lnd,LightningNetwork/lnd,ddustin/lnd,aakselrod/lnd,ddustin/lnd,AndrewSamokhvalov/lnd,LightningNetwork/lnd