Increase the flow hold count
Increase the flow hold count

The current limit of flow hold count is 4096 in Vrouter. With this
checkin this is increased to 8192. The dpdk limits are not manipulated.

Change-Id: I0292c74fde0d4c5cd867004da502e57135ca3b9e
closes-bug: #1586358

codilime/contrail-vrouter,codilime/contrail-vrouter,codilime/contrail-vrouter,codilime/contrail-vrouter