Bug 21539: addorderiso2709.pl forces librarian to select a ccode and notforloan code...

Bug 21539: addorderiso2709.pl forces librarian to select a ccode and notforloan code when using MarcItemFieldsToOrder

There is no reason that MarcItemFieldsToOrder should force librarians
to select a ccode and notforloan value for each item.
They are both optional fields.
As with location, the first value should be an empty 'none' option.

Test Plan:
1) Set up MarcItemFieldsToOrder, do *not* set mappings for ccode and notforloan
2) Add an order record to a basket that uses MarcItemFieldsToOrder
3) Note you must choose a ccode and nfl value
4) Apply this patch
5) Reload the page
6) Note you no longer have to select values for ccode and notforloan

Signed-off-by: Daniel Gaghan <daniel.gaghan@pueblolibrary.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>