Bug 15462 - Unable to renew books via circ/renew.pl

 Bug 15462 - Unable to renew books via circ/renew.pl

To verify: Got to circ/circulation.pl and try to renew an item.
Result: Can't call method "single" without a package or
        object reference at /usr/share/kohaclone/circ/renew.pl
        line 57

To test:
- Apply patch
- Try to renew items that are or are not checked out. Error
  no longer occurs.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Brendan A Gallagher <brendan@bywatersolutions.com>