qemu.org enabled HTTPS in 2017 and it should be used instead of HTTP.
There are also URLs to json.org, openvpn.net, and other domains that
support HTTPS.

This patch updates the qemu.org domains everywhere and also third-party
domains that I have checked.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20171121120435.28728-3-stefanha@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>