Can edit a search setting controlled by an environment setting

[edalzell]

Expected behaviour

Field can't be edited

Actual behaviour

Field can be edited

Steps to reproduce

1. Use Algolia & set your default index to something (I have live)
2. Set it to something else in your local environment (I have dev)
3. Go edit it.

Server configuration

Statamic version:
2.1.17

[edalzell]

Another side effect, if you have something like "{env:ALGOLIA_API_KEY}" in your search.yaml file, when you save the settings, that is overwritten w/ the actual key.

[curtisblackwell]

I see this same problem with the debug toggle in the CP settings. I have an env var set for it and I can still change it in the CP.