Don't set Legacy IP address on Windows tunnel interface within OpenConnect itself

Don't set Legacy IP address on Windows tunnel interface within OpenConnect itself

The pre-existing Windows routing connection script (vpnc-script-win.js) was
not able to reliably set the Legacy IP address of the tunnel interface, so
we've been setting it in OpenConnect itself since
60d1f092e35f05217f1c96823c4f1b86c7915bbd.

As of https://gitlab.com/openconnect/vpnc-scripts/-/merge_requests/26, we've
got vpnc-script-win.js setting the Legacy IP address correctly, and IPv6 as
well. We should leave this as the script's responsibility for
cross-platform consistency.

Signed-off-by: Daniel Lenski <dlenski@gmail.com>