RedChannelClient: use Gobject properties
RedChannelClient: use Gobject properties

Use g_param_spec_object() instead of g_param_spec_pointer() for the
'client' and 'channel' properties now that these types are GObjects.
This improves refcounting and typesafety slightly.

Signed-off-by: Jonathon Jongsma <c7254805a17bd5c41e24c3a278fcbf3afcdfb0fa@redhat.com>
Acked-by: Christophe Fergeau <05b95054a663c388a4e33d95828cb30f0370f8ef@redhat.com>

fgouget/spice,fgouget/spice,fgouget/spice,fgouget/spice