Bug 16208 - Can't delete a library EAN if the EAN value is empty

Bug 16208 - Can't delete a library EAN if the EAN value is empty

Test Plan:
1) Create an empty EAN
2) Attempt to delete it, you should get an error
3) Apply this patch
4) Attempt to delete the EAN, you should now be able to

Signed-off-by: Chris Cormack <chrisc@catalyst.net.z>
This depends on bug 16206 being pushed, or you need to apply that patch
first

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
https://bugs.koha-community.org/show_bug.cgi?id=16256

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Brendan Gallagher <bredan@bywatersolutions.com>