add missing clause for v != 5 + qos = 0

Author: SimonMacIntyre

server.go

@@ -913,6 +913,8 @@ func (s *Server) processPublish(cl *Client, pk packets.Packet) error {
 	pkx, err := s.hooks.OnPublish(cl, pk)
 	if err == nil {
 		pk = pkx
+	} else if errors.Is(err, packets.ErrRejectPacket) && (cl.Properties.ProtocolVersion != 5 || pk.FixedHeader.Qos == 0) {
+		return nil
 	} else if errors.Is(err, packets.CodeSuccessIgnore) {
 		pk.Ignore = true
 	} else if cl.Properties.ProtocolVersion == 5 && pk.FixedHeader.Qos > 0 && errors.As(err, new(packets.Code)) {