Add fixture algorithm change incorrect digest

[pwinckles]

Fixture for an object's content digest algorithm changing and one of the digests does not match the content file

[zimeon]

In this fixture the sha512 digests in the v1 manifest for all three files are incorrect. Because the error is in the manifest and not the fixity block, I think the error code should be E092 and not E093

[pwinckles]

You are right, there is a bug in my logic that decides if a digest mismatch is E092 or E093

[pwinckles]

I changed the error code to E092