nit: change unexpected http error log to warning level

[alexandrosandre]

Summary

In this error scenario the library is logging an error and raising it at the same time. This contradicts the generally adopted behavior of logging debug messages only and raising error scenarios as exceptions to the caller. As a result, callers cannot decide on their own whether they want to handle the exception silently (e.g. with their own retries) or not, because their log will always include the ERROR log of the library.

Not sure whether we should delete the log, I went for the less aggressive change in case anyone created dependencies on it.

Checklist

Delete items not relevant to your PR:

• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG
• For significant changes, documentation in https://github.com/ClickHouse/clickhouse-docs was updated with further explanations or tutorials

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[genzgd]

Yeah, exception seems like overkill :)

[alexandrosandre]

Thank you @genzgd!

[alexandrosandre]

LMK if this needs a bullet point in CHANGELOG.

[genzgd]

If you want to add it to the changelog that's fine, I'm planning on a small release probably next week.

[alexandrosandre]

Done, but not sure about your policy.

[genzgd]

I think your fork is out of date, 0.5.20 is already out. Do you mind moving it back up to the "WIP" like before?

[genzgd]

Don't worry about it, I'll add the new changelog entry.