Fix a bug about "openstack server list --user"
Fix a bug about "openstack server list --user"

Fix the bug to get the right user id.

Change-Id: Ie60a719a40654802772884ff94271b37aa061ac3
Closes-Bug: #1513701

openstack/python-openstackclient,redhat-openstack/python-openstackclient,dtroyer/python-openstackclient,BjoernT/python-openstackclient,BjoernT/python-openstackclient,redhat-openstack/python-openstackclient,openstack/python-openstackclient,dtroyer/python-openstackclient