Booking: fixed the last db upgrade script. It was trying to insert a row

Booking: fixed the last db upgrade script.  It was trying to insert a row
in config.org_unit_setting_type that had already been covered by 0109, but
which had not been in the seed data until recently, so I think one would have
only noticed this if hadn't installed a new schema from scratch in some time.

If you already ran 0323 and it worked for you, you don't have to do anything.

Also, this now avoids clobbering already-set default_elbow_room values.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@16847 dcc99617-32d9-48b4-a31d-7c20da2025e4