Bug 28344: Restore ability to issue refund against older payments

Bug 28344: Restore ability to issue refund against older payments

When implimenting the refund features into the point of sale system, it
appears that at some point we lost the ability to apply refunds against
accountlines in the historic transactions table. This patch restores
that ability.

Test plan:
1/ Add some transations via the point of sale system
2/ Navigate to the 'register details' page and note that you have the
option to refund some of the lines.
3/ Use the Cashup option to make the transactions historic
4/ Refresh the page and then select a past date to see the historic
transactions in the second datatable
5/ Note that the option to refund has not dissapeared from all lines
6/ Apply patch
7/ Refresh and note the refund option now appears as expected.

Signed-off-by: Sally <sally.healey@cheshiresharedservices.gov.uk>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>