Bug 11433: (code cleanup) remove unused 'attachbasket' op value in basket.pl

This patch cleans code in basket.pl

In basket.pl, some code is supposed to be executed if
$op eq 'attachbasket'. But it is never the case
(grep attachbasket * -r), so this condition can be removed.

No functional change expected.

Regression test only :
* Make a complete acquisition process, from the creation of a basket
 to the closure of a basketgroup, and check everything is OK
* On a basket page, try to change the basketgroup it belongs to, and
  check everything is OK
* On a basketgroup page, try to edit the content of a basketgroup (put
  a new basket in it, change the deliverybranch...), and check everything
  is OK
* On a basketgroup page, try to reopen a closed basketgroup, and close an
  open basketgroup, and check everything is OK

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>

acqui/basket.pl

@@ -189,9 +189,6 @@ if ( $op eq 'delete_confirm' ) {
         address3             => $bookseller->{'address3'},
         address4             => $bookseller->{'address4'},
       );
-} elsif ($op eq 'attachbasket' && $template->{'VARS'}->{'CAN_user_acquisition_group_manage'} == 1) {
-      print $query->redirect('/cgi-bin/koha/acqui/basketgroup.pl?basketno=' . $basket->{'basketno'} . '&op=attachbasket&booksellerid=' . $booksellerid);
-    # check if we have to "close" a basket before building page
 } elsif ($op eq 'export') {
     print $query->header(
         -type       => 'text/csv',