rpcserver: add missing channelbalance log

rpcserver.go

@@ -2173,6 +2173,9 @@ func (r *rpcServer) ChannelBalance(ctx context.Context,
 		pendingOpenBalance += channel.LocalCommitment.LocalBalance.ToSatoshis()
 	}
 
+	rpcsLog.Debugf("[channelbalance] balance=%v pending-open=%v",
+		balance, pendingOpenBalance)
+
 	return &lnrpc.ChannelBalanceResponse{
 		Balance:            int64(balance),
 		PendingOpenBalance: int64(pendingOpenBalance),