Drop location column after migration

database/2.3_migrate_locations.sql

@@ -1,2 +1,3 @@
 INSERT INTO ospos_stock_locations (location_name) (SELECT DISTINCT(location) FROM ospos_items WHERE NOT EXISTS (select location from ospos_stock_locations where location_name = location));
 INSERT INTO ospos_item_quantities (item_id, location_id, quantity) (SELECT item_id, location_id, quantity FROM ospos_items, ospos_stock_locations where ospos_items.location = ospos_stock_locations.location_name);
+ALTER TABLE ospos_items DROP COLUMN location;