Update the child_count once it's known.
Update the child_count once it's known.

svn path=/trunk/; revision=379

Pelagicore/Media-Manager-Rygel-patched,Pelagicore/Media-Manager-Rygel-patched,luisbg/rygel,Pelagicore/Media-Manager-Rygel-patched,Tarnyko/rygel,jku/rygel,jku/rygel,Tarnyko/rygel,GNOME/rygel,GNOME/rygel,GNOME/rygel