linux:~# dpkg --remove --force-depends openssh-blacklist linux:~# /etc/init.d/ssh restart
Alternative:
This works better, because openssh-blacklist would be reinstalled on each and every package operation, since it's a dependency of openssh-server.
linux:/usr/share/ssh# mv blacklist.DSA-1024 blacklist.DSA-1024.inactive linux:/usr/share/ssh# mv blacklist.RSA-2048 blacklist.RSA-2048.inactive