Increase timeout connect to allow for longer wait time.

When backend gets extremely busy especially such complex system as
openstack, increase timeout to allow for longer tcp connnection time
before the backend is deemed dead.
Refer to: http://docs.openstack.org/high-availability-guide/content/
ha-aa-haproxy.html

Change-Id: I03f5937424dc77a94eec0c03a890668a15358e01
Related-bug: #1344144