support TLS1.3 only servers

[ogmueller]

When trying to run tests on a server, which ONLY supports TLS 1.3, the analysis stops with the following error:
some.server.com:443 appears to support TLS 1.3 ONLY. You better use --openssl=<path_to_openssl_supporting_TLS_1.3>

I am using latest webnettools (johannesschafer/webnettools:latest).

Here is the full output:

###########################################################
    testssl.sh       3.1dev from https://testssl.sh/dev/

      This program is free software. Distribution and
             modification under GPLv2 permitted.
      USAGE w/o ANY WARRANTY. USE IT AT YOUR OWN RISK!

       Please file bugs @ https://testssl.sh/bugs/

###########################################################

 Using "OpenSSL 1.0.2-chacha (1.0.2k-dev)" [~183 ciphers]
 on webnettools:/testssl.sh/bin/openssl.Linux.x86_64
 (built: "Jan 18 17:12:17 2019", platform: "linux-x86_64")


 Start 2023-04-24 13:47:59        -->> 10.56.5.2:443 (some.server.com) <<--

 rDNS (10.56.5.2):       some.server.com. some.
 some.server.com:443 appears to support TLS 1.3 ONLY. You better use --openssl=<path_to_openssl_supporting_TLS_1.3>