Use kernel sandbox for ssh

src/freedombone-utils-ssh

         echo "KexAlgorithms $SSH_KEX" >> /etc/ssh/sshd_config
     fi
     sed -i "s|#KexAlgorithms $SSH_KEX|KexAlgorithms $SSH_KEX|g" /etc/ssh/sshd_config
+    sed -i 's|#UsePrivilegeSeparation .*|UsePrivilegeSeparation sandbox|g' /etc/ssh/sshd_config
+    sed -i 's|UsePrivilegeSeparation .*|UsePrivilegeSeparation sandbox|g' /etc/ssh/sshd_config
 
     apt-get -yq install fail2ban vim-common