TalkMaster: Switch master if dialed is secondary

When connecting to a master node, the client needs to try a different
master if the initially tried one is a secondary master node. This
statement wasn't implemented yet before this patch and therefore it was
good luck if the initally tried master was the primary one - and the
connection worked - or if it was a secondary master - and the client
got stuck in re-trying the same node forever. This patch makes NEO/go
usage with clusters of more than one master therefore much more stable.

go/neo/mastered.go

@@ -132,18 +132,14 @@ func (node *_MasteredNode) TalkMaster(ctx context.Context, f func(context.Contex
 			return err // M commands to shutdown
 		}
 
-		log.Warning(ctx, errors.Cause(err))
-
-		var unexpectedMsg *neonet.ErrUnexpectedMsg
-		if errors.As(err, &unexpectedMsg) {
-		    if unexpectedMsg.MsgCode == proto.MsgCode(&proto.NotPrimaryMaster{}) {
-			log.Warning(ctx, unexpectedMsg.MsgCode)
-			log.Warning(ctx, unexpectedMsg.Msg)
-		    }
+		var notPrimaryMaster *proto.NotPrimaryMaster
+		if errors.As(err, &notPrimaryMaster) {
+			primary := notPrimaryMaster.KnownMasterList[notPrimaryMaster.Primary]
+			node.MasterAddr = fmt.Sprintf("[%s]:%v", primary.Host, primary.Port)
+			return err
 		}
 
 		// TODO if err == "reject identification / protocol error" -> shutdown client?
-		// TODO if err == "not a primary" -> try redirected address
 
 		// exit on cancel / throttle reconnecting
 		select {