Fix warnings in haproxy config

Haproxy config check(/usr/sbin/haproxy -c -f /etc/haproxy/haproxy.cfg)
returns 3 warnings:

1. keyword 'forceclose' is deprecated in favor of 'httpclose', and will
not be supported by future versions.
2. backend 'galera-back' : 'option tcplog' directive is ignored in
backends.
3. 'http-request' rules ignored for backend 'galera-back' as they
require HTTP mode.

This change fixes 1. and 2.
Fixing 3. will be a bit more tricky as it's a part of
`openstack_haproxy_stick_table` defined in
/opt/openstack-ansible/inventory/group_vars/haproxy/haproxy.yml

Change-Id: Idaa4b5580039857435f90416924dee26a702deba

defaults/main.yml

@@ -208,7 +208,7 @@ haproxy_server_timeout: "50s"
 # Set the HTTP keepalive mode to use
 # Disable persistent connections by default because they can cause issues when the server side closes the connection
 # at the same time a request is sent.
-haproxy_keepalive_mode: 'forceclose'
+haproxy_keepalive_mode: 'httpclose'
 
 
 ## haproxy tuning params

templates/service.j2

@@ -108,8 +108,6 @@ backend {{ item.service.haproxy_service_name }}-back
 {% endif %}
 {% if request_option == "http" %}
     option forwardfor
-{% elif request_option == "tcp" %}
-    option tcplog
 {% endif %}
 {% for option in backend_options %}
     option {{ option }}