multi: add new config QuiescenceTimeout

This commit makes removes the `defaultQuiescenceTimeout` and makes it
configurable as different nodes have different network environment. In
addition the default timeout has been increased from 30s to 60s.

lncfg/htlcswitch.go

@@ -11,11 +11,21 @@ var (
 	// where both side send 483 payments at the same time to stress test
 	// lnd.
 	MaxMailboxDeliveryTimeout = 2 * time.Minute
+
+	// minQuiescenceTimeout specifies the minimal timeout value that can be
+	// used for `QuiescenceTimeout`.
+	minQuiescenceTimeout = 30 * time.Second
+
+	// DefaultQuiescenceTimeout specifies the default value to be used for
+	// `QuiescenceTimeout`.
+	DefaultQuiescenceTimeout = 60 * time.Second
 )
 
 //nolint:ll
 type Htlcswitch struct {
 	MailboxDeliveryTimeout time.Duration `long:"mailboxdeliverytimeout" description:"The timeout value when delivering HTLCs to a channel link. Setting this value too small will result in local payment failures if large number of payments are sent over a short period."`
+
+	QuiescenceTimeout time.Duration `long:"quiescencetimeout" description:"The max duration that the channel can be quiesced. Any dependent protocols (dynamic commitments, splicing, etc.) must finish their operations under this timeout value, otherwise the node will disconnect."`
 }
 
 // Validate checks the values configured for htlcswitch.
@@ -30,5 +40,10 @@ func (h *Htlcswitch) Validate() error {
 			MaxMailboxDeliveryTimeout)
 	}
 
+	if h.QuiescenceTimeout < minQuiescenceTimeout {
+		return fmt.Errorf("quiescencetimeout: %v below minimal: %v",
+			h.QuiescenceTimeout, minQuiescenceTimeout)
+	}
+
 	return nil
 }