Bug 21075: AutoUnsuspendHolds should unsuspend holds <= today

Bug 21075: AutoUnsuspendHolds should unsuspend holds <= today

To recreate:
 1 - Place a hold in your system
 2 - Set that hold (or all holds) to expire today
    update reserves set suspend_until=CONCAT( CURDATE()," 00:00:00");
 3 - Run misc/cronjobs/holds/auto_unsuspend_holds.p
 4 - Note the hold is sitll suspended
 5 - Visit /cgi-bin/koha/reserve/request.pl for the book with the hold
 6 - Note the suspend date is tomorrow (and cannot be set to today]
 7 - Click update holds - the date in db is now set to tomorrow
 8 - Reset to today
 9 - Apply patch
10 - Run the cron again
11 - Visit the page and note hold is unsuspended

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>