Remove dodgy rescue_from

This caught me recently when publishing an edition that had invalid previous editions. The error gets swallowed and a cryptic error message is shown to the user:

`Unable to publish this edition because it is invalid (). Please edit it and try again`

This is despite the fact that the edition has actually been published just fine; it's just the previous editions that have not been transitioned to archived.

I think this will be causing all sorts of insidious problems within the app and we should remove it asap, even if it is likely to increases the chances of users seeing 500 errors when they perform workflow actions on editions. Our approach should be to aggressively fix any issues that are causing the app to attempt invalid transitions, rather than to catch exceptions and brush things under the carpet.