R1:f5a9d1f8d47b

Raise a setup issue for misconfigured Elasticsearch

Summary: Fixes T8274. That report is very light on details, but I think the issue is that their Elasticsearch is misconfigured and the new setup warning dies a little too hard if the server is just completely dead.

Test Plan: Set `search.elastic.host` to an invalid server, got a similar-looking exception (?), applied patch, got a setup warning instead.

Reviewers: btrahan, joshuaspence

Reviewed By: btrahan, joshuaspence

Subscribers: epriestley…