Bug 15923: Take the id list file into account when exporting records

Bug 15923: Take the id list file into account when exporting records

When exporting records (tools/export.pl or misc/export_records.pl), a
file of ids (authid or biblionumber) can be passed to filter the
results.
Bug 14722 has broken this behavior.

Test plan:
Export records and specify a list of records to filter the results.
Prior to this patch, the record with the id 1 was exported.

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com