Bug 21464: Fix overdue list export

Bug 21464: Fix overdue list export

  commit e09ed656af5f75a82ccfa29318081e217618c32d
  Bug 18403: Only display libraries from group in dropdown lists
and
  commit 0ab22e1c7c6b6e8d14a4fb7478ab2a3d42da347d
  Bug 18789: Send Koha::Patron object to the templates

broke the overdue list export.

Test plan:
Create some overdues
Export them: "Home › Circulation › Overdues" then click the link on top
of the table.
All the different columns of the generated CSV file must be filled
correctly

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>