BSD Syslog from mikrotik not parsed

Hello, I need to receive logs from a Mikrotik router but found it does not work 100%.

There in an option in Mikrotik settings named 'bsd-syslog' which in their docs says "whether to use bsd-syslog as defined in RFC 3164".

## Expected Behavior

Receive 'bsd style' syslog messages without tweaking any further. That way Graylog could process the full message.

## Current Behavior
Messages are received only without 'bsd-syslog' setting. 'Allow overriding date' has to be enabled too, in Graylog's input.

Received messages don't have their information extracted automatically.

## Context

I've linked a pcap from the graylog server which show both kind of messages. The first two, are sent with 'bsd-syslog' and NOT received into graylog, last three are received ok but messages are saved into the full_message field only, nothing is extracted.
```
full_message
system,info,account mk_MDZi: user example logged out from 200.12.34.56 via winbox
```

Pcap: https://filebin.net/ardm8t32t26fevhy

Im learning about graylog, but without this, more work has to be done to process incoming messages.

## Your Environment

* Graylog Version: 3.2.4+a407287
* Elasticsearch Version: 6.8.8
* MongoDB Version: 3
* Operating System: Ubuntu amd64 / Docker