LP#1568195: fix retrieving big OUS batches

LP#1568195: fix retrieving big OUS batches

This patch fixes a regression introduced in LP#1501471
where the Library Settings Editor could fail to retrieve
the values of org unit settings if more than 99 were
requested at a time.

To test
-------
[1] Open the XUL library settings editor and ensure that
    no search filters are in effect. Note that values
    are not displayed for any of the OU settings, and that
    the Pg log contains error messages like this:

    "ERROR: cannot pass more than 100 arguments to a function"

[2] Apply the patch.
[3] Repeat step one, and verify that values are now retrieved
    for all of the OU settings that have values set.

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