Close METADAPT-A transaction channel

metadapta.go

@@ -109,6 +109,7 @@ func (this *a) sendMessageSafe(trans int64, method uint16, data []byte) error {
 func (this *a) receive() {
 	defer func() {
 		this.underlying.Close()
+		close(this.transChan)
 		this.transLock.Lock()
 		defer this.transLock.Unlock()
 		for _, trans := range this.transMap {