allmydata.immutable.offloaded.LocalCiphertextReader claims to implement IEncryptedUploadable but does not implement set_upload_status

[exarkun]

At best, this means there's some current or future codepath where someone tries to use a LocalCipherTextReader? as if it were an IEncryptedUploadable and creates a bug because it isn't really one.

More realistically, I think this is a symptom of the way status is propagated through the system relying on an interface that conflates unrelated things. We should probably look at changing the way statuses work so that not every thing that we might want to watch for status needs these duplicative methods.