Errors from old\removed lookup tables in logs

Hi,

May not be the best place to post this (reply to old thread), but it seems related.

I have an issue - fairly minor but annoying - that I am getting the following entries logged. I think this is because I renamed some lookup tables. I have fairly much wiped them out and started again now - I removed the extractors that referenced them, and the input, and re-created from scratch, but I'm still getting these errors logged as if the old data is being held somewhere:-

```
2019-03-24T15:27:42.292Z ERROR [InputServiceImpl] Cannot build extractor from persisted data. Skipping.
java.lang.IllegalStateException: Configured lookup table doesn't exist
at org.graylog2.inputs.extractors.LookupTableExtractor.(LookupTableExtractor.java:57) ~[graylog.jar:?]
```

Note that I'm using GL 3.0.0.

Rgds

_Originally posted by @urban-moniker in https://github.com/Graylog2/graylog2-server/issues/3602#issuecomment-475970445_