hard coded http timeout in haproxy_server role template

Dear all,

In our private cloud, we experienced some timeout issues in haproxy.
Some API requests took more than 50 seconds.

As we found out in current haproxy_server role haproxy.cfg.j2 template. The timeout are unfortunately hard coded, and there is no variable which you could use to override them.

Snippet of current haproxy.cfg.j2 template.

-----------------------------------------------------------------
defaults
        log global
        option dontlognull
        option redispatch
        retries 3
        timeout client 50s
        timeout connect 10s
        timeout http-request {{ haproxy_http_request_timeout }}
        timeout server 50s
        maxconn 4096
-----------------------------------------------------------------

I will implement some new variables which could be used to override timeout.