`http` protocol used at some point during human-readable slug redirects in lower environments

At some point during the URL rewriting process for works, redirects use `http` instead of `https` in both testing and staging environments.

### Evidence / Screenshot (if possible)

_Note the "Location" in the response headers._

### Relevant url?

Compare the redirects for the following URLs:

https://testing.openlibrary.org/authors/OL5017833A/foo
https://openlibrary.org/authors/OL5017833A/foo

### Steps to Reproduce

1. With the dev tools network tab open, go to https://testing.openlibrary.org/authors/OL5017833A/foo
2. Note that this redirects to an `http://` URL

* Actual: HTTP is used during redirects
* Expected: HTTPS is used during redirects

### Details

- **Logged in (Y/N)?** N/A
- **Browser type/version?** Firefox 92.0
- **Operating system?** N/A
- **Environment (prod/dev/local)?** testing and staging

### Proposal & Constraints

### Related files

### Stakeholders

@RayBB
@cdrini