Config overhaul: make secrets mandatory #1006
Description
Parent issue: #938
Relates to:
- Config overhaul: make some fields mandatory #938
- Config overhaul: make some fields mandatory torrust-index#673 (comment)
- Config overhaul: make secrets mandatory torrust-index#710
Remove default value for http_api.access_tokens.admin.
The option core.database.path might also contain secrets when the DB driver is MySQL. However, the default driver is SQLite.