Don't delete DH params if they aren't created

src/freedombone-clientcert

@@ -108,7 +108,6 @@ openssl ca -config /etc/ssl/dovecot-ca.cnf -in /etc/ssl/requests/$USERNAME.csr -
 
 # move the cert to the user's home
 mkdir /home/$USERNAME/emailcert
-shred -zu /etc/ssl/certs/$USERNAME.dhparam
 mv /etc/ssl/certs/$USERNAME.cer /home/$USERNAME/emailcert
 cp /etc/ssl/certs/dovecot-ca.crt /home/$USERNAME/emailcert
 mv /etc/ssl/private/$USERNAME.key /home/$USERNAME/emailcert