Bug 9046: FIX wrong test on an arrayref instead of an array

EmbedItemsInMarcBiblio does not embed items when the itemnumbers param
is given. That breaks the export tools (used from commandline).

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Bug 9046: Followup FIX perl v.10 raises an error if itemnumbers if undefined

If the itemnumbers parameter is undef, perl raises an error :
"Can't use an undefined value as an ARRAY reference"

Signed-off-by: Mason James <mtj@kohaaloha.com>