Hello!

I have an issue.

Knot is configured as a secondary server, and when receiving a zone, a "trailing data" error occurs, preventing the zone from being loaded from the primary server.

```
Jan 30 11:03:40 hostname knotd[5407]: info: [domain.com.] refresh, remote 50788646-db98-4caa-b26e-95b30a470796, address 1.2.3.4@53, failed (trailing data)
```

The same warning appears when using the `kdig` utility:

```bash
kdig @1.2.3.4 domain.com AXFR > /tmp/domain.com
;; WARNING: malformed reply packet (trailing data)
;; WARNING: malformed reply packet (trailing data)
```

The issue occurs specifically with large zones. If the zone requires 2 messages to be received (e.g., `Received 32720 B (2 messages, 442 records)`), one warning appears. If it requires 3 messages (e.g., `Received 49083 B (3 messages, 878 records)`), two warnings appear.

However, if I place this zone (`/tmp/domain.com`) into `/var/lib/knot` and then execute:

```bash
knotc reload
knotc zone-refresh domain.com
```

Knot successfully loads the zone.

Unfortunately, due to confidentiality, I cannot share the contents of the zone. Additionally, I do not have precise information about the software installed on the primary server. However, if BIND is used as the secondary server, there are no issues. A regular `dig` command also does not return any errors.

Is there any way to make Knot ignore the "trailing data" error and successfully load the zone?

Thank you for your help!