Icrease haproxy timeouts for mysql connections

Haproxy often breaks mysql connections that results in
"MySQL server has gone away" or similar because of 1 minute
timeouts. Instead the timeouts should be not less than mysql
connections timeouts - in most cases set to 3600s by default
by OpenStack projects.

Change-Id: Ic364f6942cdc6c2f274a508ae548bf964b098da4
Closes-Bug: #1645098

ansible/roles/haproxy/templates/haproxy.cfg.j2

@@ -638,6 +638,8 @@ defaults
 {% if enable_mariadb | bool %}
 listen mariadb
   mode tcp
+  timeout client 3600s
+  timeout server 3600s
   option tcplog
   option tcpka
   option mysql-check user haproxy post-41