_TypeError: Null check operator used on a null value

Sentry Issue: [INTIFACE-CENTRAL-Z](https://nonpolynomial.sentry.io/issues/4532841475/?referrer=github_integration)

```
_TypeError: Null check operator used on a null value
  File "sorter.dart", line 41, in MessageSorter.checkMessage
  File "client.dart", line 41, in ButtplugClient.connect.<fn>
...
(4 additional frame(s) were not displayed)
```