Current fedmsg deduplication code seems to only compare item, checkname and outcome. But I think that's incorrect, because it should also compare arch. Currently, if the first arch tested passes or fails, and any further arches tested have the same result, we will never send out fedmsgs for them and our receivers will not be informed that those archs were successfully tested (which means they would have to poll for this information).

So, if arch is different, we should not deduplicate.