Bug 22619: Fix null empty behaviour for new rules

Bug 22619: Fix null empty behaviour for new rules

To test:
 1 - Go to Admin->Circulation and fines rules
 2 - Set All/All rules ot have a limit for Current checkouts allowed (and onsite checkouts allowed)
 3 - Select an itemtype to add a new rule
 4 - Save without entering any values
 5 - Note that new rule displays with the same numebr as the all/all rule
 6 - Check the DB, not no lines were added to circulation_rules table
 7 - Delete the rule from the staff client
 8 - Apply patch
 9 - Repeat, note the new rule is unlimited
10 - Run selenium tests
11 - They pass!
12 - Check no rules/itemtypes are added to your system by the tests

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>