Acq + Vandelay : exit early for 'load bibs and items' in picklist

Acq + Vandelay : exit early for 'load bibs and items' in picklist

The ACQ UI does not support loading bibs and items directly from the
picklist interface.  If the user selects "load bibs and items" from the
picklist page they will be presented with the vandelay options, but the
actual upload/merge/etc will not do anything.  This change prevents the
vandelay options from showing in this case.

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Ben Shum <bshum@biblio.org>