Bug 7431: Fixes the display of the due date in opac item specific holds.

Bug 7431: Fixes the display of the due date in opac item specific holds.

Fixes the reference to the due date in opac-reserve from date_due to dateDue as defined int opac-reserve.pl.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
(cherry picked from commit cf15a0e427d8b8166d1dde8dae6ad6bf1a6f7de9)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>
(cherry picked from commit 7b7f04effae0abe676830b5d3a5471cc992f323a)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>