Rudder

Quite frequently, the "started on" column for the "processes" tab in node details view is full of "Bad format" in place of a date.

This can be due to two causes:

- we actually don't have the date, in which case we MUST display that information in place of "bad format",
- we had a date in the inventory report, but not in the the iso-8601 short format, what happens most of the time. In that case, we should just keep the date. Better to have something a human can try to parse with its brain than nothing at all.