external: Update child-count after D-Bus signal
external: Update child-count after D-Bus signal

https://bugzilla.gnome.org/show_bug.cgi?id=669680

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