Soften a possible cluster search setup fatal
Ref T12450. The way that config repair and setup issues interact is kind of complicated, and if cluster.search is invalid we may end up using cluster.search before we repair it.
I poked at things for a bit but wasn't confident I could get it to consistently repair before we use it without doing a big messy change.
The only thing that really matters is whether "type" is valid or not, so just put a slightly softer/more-tailored check in for that.
- With "type": "elastic", loaded setup issues.
- Before patch: hard fatal.
- After patch: softer fatal with more useful messaging.
Reviewed By: chad
Maniphest Tasks: T12450
Differential Revision: https://secure.phabricator.com/D17576