packaging: setup: drop all objects

Instead of 'drop owned cascade', use cleandb.sh from dbscripts.

Change-Id: I2f34be79cbf4eec9f18f33dd735ba0c1fff00d92
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1049468
Signed-off-by: Yedidyah Bar David <didi@redhat.com>