Forcing UTF-8 encoding for whois.ripe.net breaks --list-versions, --diff-versions and --show-version flags

[bcollet]

Changes introduced by 9bb383e broke --list-versions, --diff-versions and --show-version flags on whois.ripe.net:

% whois --verbose AS202945 --list-versions
Using server whois.ripe.net.
Query string: "-V Md5.6.6 --list-versions --charset UTF-8 as202945"

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://docs.db.ripe.net/terms-conditions.html

%ERROR:109: invalid combination of flags passed
%
% The flags "--list-versions" and "-Z, --charset" cannot be used together.

% This query was served by the RIPE Database Query Service version 1.121 (ABERDEEN)

Using v.5.6.0 or earlier yields the expected result:

% whois --verbose AS202945 --list-versions
Using server whois.ripe.net.
Query string: "-V Md5.6.0 --list-versions as202945"

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://docs.db.ripe.net/terms-conditions.html

% Version history for AUT-NUM object "as202945"
% You can use "--show-version rev#" to get an exact version of the object.

rev#  Date              Op.

1     2016-04-28T14:21:23Z  ADD/UPD
2     2016-04-28T15:08:03Z  ADD/UPD
3     2016-04-28T15:53:19Z  ADD/UPD
[omitted for brevity]
58    2026-02-06T17:43:40Z  ADD/UPD

% This query was served by the RIPE Database Query Service version 1.121 (SHETLAND)