LP#904581: when calculating hold status, be more careful about fetching transits

LP#904581: when calculating hold status, be more careful about fetching transits

This patch fixes a problem where if a hold meets the following
criteria, an "Invalid date format: at /usr/share/perl5/Error.pm"
error can be thrown when fetching its details:

- the hold has a captured item
- the captured item has status 8 (on hold shelf)
- there is another item that is currently in transit to fill the hold
- the pickup library (or one of its ancestors) has the
  circ.hold_shelf_status_delay library setting set.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Ben Shum <bshum@biblio.org>