Stop directly accessing the Object::properties field data
structure and instead use the formal object property iterator
APIs. This insulates the code from future data structure
changes in the Object struct.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Tested-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>