Bug 17782 - Patron updated_on field should be set to current timestamp when borrower...

Bug 17782 - Patron updated_on field should be set to current timestamp when borrower is deleted

To test:
01 Find a patron
02 Get the updated_on value from the db in borrowers table
03 Delete the patron
04 Get the update_on value from the db on deletedborrowers table
05 Values from 02 and 04 are the same
06 Apply patch
07 Repeat 01-04
08 Values should now be different

Signed-off-by: Claire Gravely <claire_gravely@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>