rpc: use default if conf-target is not set

This commit uses the new coop-close-target-confs value as the default to
use for a nodes self initiated channel closures if the conf-target flag
for the channel closure is not set. The defaults for both these options
is 6 so this shouldnt change current behaviour.

rpcserver.go

@@ -2317,6 +2317,13 @@ func (r *rpcServer) CloseChannel(in *lnrpc.CloseChannelRequest,
 				"is offline (try force closing it instead): %v", err)
 		}
 
+		// If conf-target is not set then use the conf-target used for
+		// co-op closes that are initiated by the remote peer.
+		targetConf := uint32(in.TargetConf)
+		if targetConf == 0 {
+			targetConf = r.cfg.CoopCloseTargetConfs
+		}
+
 		// Based on the passed fee related parameters, we'll determine
 		// an appropriate fee rate for the cooperative closure
 		// transaction.
@@ -2325,7 +2332,7 @@ func (r *rpcServer) CloseChannel(in *lnrpc.CloseChannelRequest,
 		).FeePerKWeight()
 		feeRate, err := sweep.DetermineFeePerKw(
 			r.server.cc.FeeEstimator, sweep.FeePreference{
-				ConfTarget: uint32(in.TargetConf),
+				ConfTarget: targetConf,
 				FeeRate:    satPerKw,
 			},
 		)