Failure when copying missing iso

[egli]

• it fails on line 215 of archive.clj where it tries to copy the iso file to the right place where the archiving process expects it. For some reason this iso file doesn't exist.
• this is happening inside a transaction which rolls back the db changes
• so the exception needs to happen so that the transaction does the roll back
• if an exception happens in the message listener the message is queued for redelivery. This is of course bad. It should not be redelivered if the iso is missing.
• the question is what to do if an iso is missing. Something is clearly wrong. Should we even archive master?

[egli]

This is no longer handled with the message queue that does redelivery. With the new code it simply logs an error