Bug 37954: Fix barcode column name

Bug 37954: Fix barcode column name

Patch https://github.com/Koha-Community/Koha/commit/6cbbfa2 changed
holdings_barcode to holdings_barcodes

I believe this caused the configuration from the table to no longer
work (barcodes!=barcode)

Test plan:
1) Access any bibllio:
   <staff_url>/cgi-bin/koha/catalogue/detail.pl?biblionumber=76
2) On the top right of the table, click 'Configure'
3) Expand 'Catalog', search for 'holdings_barcode'. Tick 'is hidden by
   default'. Save.
4) Visit the biblio again, notice the column is still showing.
5) Apply patch. Restart all + flush_memcached. Repeat.
6) Bonus: On the table, click 'Show filters'. Make sure barcode
   filtering still works.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>