fix: only check the noSendWaiting option; ignore multicast/unicast

The current check for multicast and unicast is not correct, and is
also unnecessary; we should only check the noSendWaiting option.

channel.go

@@ -103,9 +103,13 @@ func (c *channel) deleteRouter(msgID uint64) {
 }
 
 func (c *channel) sendMsg(req request) (err error) {
-	// unblock the waiting caller unless noSendWaiting is enabled
 	defer func() {
-		if req.opts.callType == E_Multicast || req.opts.callType == E_Unicast && !req.opts.noSendWaiting {
+		// While the default is to block the caller until the message has been sent, we
+		// can provide the WithNoSendWaiting call option to more quickly unblock the caller.
+		// Hence, after sending, we unblock the waiting caller unless noSendWaiting is enabled.
+		// If noSendWaiting is enabled, the calling call type will not block on the response
+		// channel, and the receiver goroutine below will call routeResponse to delete the router.
+		if !req.opts.noSendWaiting {
 			c.routeResponse(req.msg.Metadata.MessageID, response{})
 		}
 	}()

multicast.go

@@ -38,8 +38,7 @@ func (c RawConfiguration) Multicast(ctx context.Context, d QuorumCallData, opts
 
 	// nodeStream sends an empty reply on replyChan when the message has been sent
 	// wait until the message has been sent
-	for sentMsgs > 0 {
+	for ; sentMsgs > 0; sentMsgs-- {
 		<-replyChan
-		sentMsgs--
 	}
 }