Previously, `EncryptedConfiguration` was [updated][1] to use
`InheritableOptions` so that keys could be called like methods. It was
later [updated again][2] to ensure that it behaved both like a `Hash` and
`OrderedOptions`. In this second change, the `InheritableOptions`
instance was accidentally nested with another `InheritableOptions`
instance.

This continued to mostly work as expected because `InheritableOptions`
will fall back to the inner `InheritableOptions` when the outer one
doesn't have a key. However, any methods that try to treat the outer
`InheritableOptions` like it should know about all of its keys will fail
(for example, `#keys`, `#to_h`, `#to_json`, etc.)

This commit fixes the issue by removing the extraneous outer
`InheritableOptions` instance.

[1]: a6a9fed1
[2]: 80585daf