iotests.py: don't abort if IMGKEYSECRET is undefined
Instead of using os.environ[], use .get with a default of empty string
to match the setup in check to allow us to import the iotests module
(for debugging, say) without needing a crafted environment just to
import the module.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <
20181221093529.23855-6-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>