Bug 30324: Don't use default rule if we have a parent rule

Bug 30324: Don't use default rule if we have a parent rule

Currenty, if we find only a defult rule for a checkout we are ignoring the parent rule.
We should not use the default if there is a parent rule

To test:
 1: have an itype BK
 2: create an itype BK2, set BK as the parent to BK2
 3: create a circ rule for All Patrons, item type BK (displays as "Books (All)" in the circ rules interface), setting total checkouts to 1
 4: do not create any rule specifically for the BK2 itype
 5: have some BK items and some BK2 items
 6: check a BK item out to a patron
 7: check a BK2 item out to the same patron, observe you are not blocked from doing so
 8: try to check out a second BK2 item to the same patron, get message "Too many checked out. 1 checked out, only 1 are allowed."
 9: try to check out a second BK item to the same patrons, get message "Too many checked out. 2 checked out, only 1 are allowed."
10: return both items
11: check a BK2 item out to your patron
12: try to check a BK item out to your patron, get message "Too many checked out. 1 checked out, only 1 are allowed."
13: Apply patch
14: Repeat 7, you are now blocked
15: Other results should be the same

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Michael Adamyk <madamyk@ckls.org>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>