Remove now-unused database_config_whitelist

docs/docs/configuration/cheatsheet.md

@@ -1016,21 +1016,6 @@ git clone <MY MODULE>
 
 Boolean, enables/disables in-database configuration. Read [Transfering the config to/from the database](../administration/CLI_tasks/config.md) for more information.
 
-## :database_config_whitelist
-
-List of valid configuration sections which are allowed to be configured from the
-database. Settings stored in the database before the whitelist is configured are
-still applied, so it is suggested to only use the whitelist on instances that
-have not migrated the config to the database.
-
-Example:
-```elixir
-config :pleroma, :database_config_whitelist, [
-  {:pleroma, :instance},
-  {:pleroma, Pleroma.Web.Metadata},
-  {:auto_linker}
-]
-```
 
 ### Multi-factor authentication -  :two_factor_authentication
 * `totp` - a list containing TOTP configuration