trivial: Remove now-unnecessary device-changed callback
trivial: Remove now-unnecessary device-changed callback

In verbose mode this actually makes the progressbar not work as
well and is not needed since the device changed does come with the
progress bar.

hughsie/fwupd,fwupd/fwupd,vathpela/fwupd,fwupd/fwupd,vathpela/fwupd,vathpela/fwupd,hughsie/fwupd,hughsie/fwupd,fwupd/fwupd,hughsie/fwupd,vathpela/fwupd,fwupd/fwupd