Revert "I.1.0.0: use haproxy CLI to start the service"

This reverts commit 73d62c3307a2dc4866931178c6de21bc3f165ebf.
It's not the good way to manage HAproxy.
Previously, this task did not work because of eDeploy upgrade which
ignored new HAproxy init scripts. So HAproxy could not start during a
failover.
This revert enables again the right way to ensure HAproxy is running.