RM: nvidia-settings -- ROM; moving from contrib to main

[Vincent Cheng]

Ping? Is there anything that we (well, the pkg-nvidia team) can do to
get this fixed, or is this just waiting on ftpmaster action?
nvidia-settings has been uninstallable in sid for about a month due to
this bug; this is also blocking re-upload of conky-all back to the
archive (which was removed prematurely by ftpmaster; #750975).

Regards,
Vincent