Fix RHL exception bug.
Fix RHL exception bug.

When raising an exception for an unknown RHL update, we were
using the old "update" instead of "tdl.update", which means we
would have raised an exception while raising an exception.
Fix it here.

Signed-off-by: Chris Lalancette <60b62644009db6b194cc0445b64e9b27bb26433a@redhat.com>

NeilBryant/oz,mgagne/oz,ndonegan/oz,nullr0ute/oz,moofrank/oz,imcleod/oz,nullr0ute/oz,cernops/oz,mgagne/oz,clalancette/oz,clalancette/oz,imcleod/oz,cernops/oz,NeilBryant/oz,moofrank/oz,ndonegan/oz