Bug 10544: (follow-up) update MARC21 DOM index definitions

Bug 10544: (follow-up) update MARC21 DOM index definitions

This patch updates the MARC21 DOM index definitions to
index the 952$i as 'Number-local-acquisition' rather than
'stocknumber'.

To test (for a MARC21/DOM setup):

[1] Copy the MARC21 biblio-zebra-indexdefs.xsl over to the
    active Zebra configuration directory.
[2] Reindex the bib records.
[3] Verify that 'stocknumber', 'inv', and 'number-local-acquisition'
    searches work.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>