DEICH-5641 update contet of column 'Date' in kemnersaker table in koha intra

The value is now due date (forfallsdato), or the string "levert" if
the issue is returned.

koha/koha-tmpl/intranet-tmpl/prog/en/includes/kemnersaker.inc

@@ -6,13 +6,13 @@
  <table>
  <thead>
  <tr>
- <th>Dato</th><th>Tittel</th><th>Strekkode</th>
+ <th>Forfallsdato</th><th>Tittel</th><th>Strekkode</th>
  </tr>
  </thead>
  <tbody>
  [% FOREACH saker %]
  <tr>
- <td>[% timestamp | $KohaDates %]</td><td>[% title %]</td><td>[% barcode %]</td>
+ <td>[% IF returndate %]levert[% ELSE %][% date_due | $KohaDates %][% END %]</td><td>[% title %]</td><td>[% barcode %]</td>
  </tr>
  [% END %]
  </tbody>