REGTEST: Add a reg test for health-checks over SSL/TLS.

REGTEST: Add a reg test for health-checks over SSL/TLS.

This script runs two tests. One with "httpchk" over SSL/TLS and another
one with "check-ssl" option. As varnishtest does not support SSL/TLS
we use two haproxy processes to run these tests. h2 haproxy process
be2 and be4 backends declare one server each wich are the frontend
of h1 haproxy process. We check the layer6/7 checks thanks to syslog
messages.

Signed-off-by: Frédéric Lécaille <flecaille@haproxy.com>