Fix client constructor for zaqar-bench
Fix client constructor for zaqar-bench

The client version is not an optional argument for constructing zaqar
client instance. This patch adds 1.1 as the default version.

Change-Id: I8f51b1f4d6e55882309586b21fdf7940ca0f6dce

openstack/zaqar,openstack/zaqar,openstack/zaqar,openstack/zaqar