Switching a data node from secure to insecure needs Graylog restart

If I change a datanode to run with `insecure_startup=true`

Graylog keeps trying to use TLS until I restart it:
```
2024-04-11T20:44:39.585Z ERROR [VersionProbe] Unable to retrieve version from Elasticsearch node: Unsupported or unrecognized SSL message. - Unsupported or unrecognized SSL message.
2024-04-11T20:44:39.586Z INFO [VersionProbe] OpenSearch/Elasticsearch is not available. Retry #26
2024-04-11T20:44:40.052Z WARN [Messages] Caught exception during bulk indexing: ElasticsearchException{message=OpenSearchException[An error occurred: ]; nested: IOException[Unrecognized SSL message, plai
ntext connection?]; nested: SSLException[Unrecognized SSL message, plaintext connection?];, errorDetails=[]}, retrying (attempt #18).

```

Ideally the VersionProbe would know that the DataNode got reconfigured.

## Your Environment

* Graylog Version: 6.0.0.rc2