server: Don't lose LastChange events
server: Don't lose LastChange events

Once sent, the boolean flag was set to true but never reset to false again so
only the event added last would show up in the LastChange that were sent
afterwards.

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