Bug 25417: Prevent negative debit amount on backdating returns
Koha::Account->add_credit is expecting a positive amount.
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com> Signed-off-by: Didier Gautheron <didier.gautheron@biblibre.com> Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com> Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com> Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com> Signed-off-by: Joy Nelson <joy@bywatersolutions.com>