jwhois: fix path to lynx in $lynx/etc/jwhois.conf

Close #8696.
Fixes issues found when jwhois attempts to launch terminal browser
(lynx) for HTTP whois queries, for example:

    $ whois blah.io
    [Querying http://www.io.io/cgi-bin/whois]
    [HTTP: Unable to run web browser: /usr/bin/lynx: No such file or directory]

Tested via:

    grep lynx \
      /nix/store/bymgmn2vvw1n7nbb1isy87xg94s8f2ml-jwhois-4.0/etc/jwhois.conf \
      | cut -f2 -d'"' \
      | xargs stat -t