Bug 16913: Koha::Patrons - Remove GetBorrowersNamesAndLatestIssue

Bug 16913: Koha::Patrons - Remove GetBorrowersNamesAndLatestIssue

This subroutine has been added by
  commit 5904681faca77c87ff8071414d66e123a2d3baa9
  Date:   Wed Mar 19 10:11:12 2008 -0500
    CleanBorrowers fixing.
but has never been used.
It can be removed safely.

Test plan:
  git grep GetBorrowersNamesAndLatestIssue
should not return any results.

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>