Bug 21738: check items count in C4:ILSDI::HoldTitle

Bug 21738: check items count in C4:ILSDI::HoldTitle

Test plan:
  - Try holding a title without items via ILS-DI
    (cgi-bin/koha/ilsdi.pl?service=HoldTitle&patron_id=1&bib_id=1),
  - you get an error,
  - apply this patch,
  - try again,
  - you should get the code "Notitems"Bug 21738: check items count in
    C4:ILSDI::HoldTitle

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>