dinstall: rsync dep11 data for non-free-firmware too

Seeing https://appstream.debian.org/sid/non-free-firmware/index.html it looks like the appstream service noticed the addition of the non-free-firmware component, but I'm not 100% certain empty indices are present at the moment, so maybe apply the proposed patch with some caution. ;)

Hopefully firmware packages with appstream metadata will reach non-free-firmware soon anyway.