all_tenants=0 should not return instances from all tenants

Fixes set up of server list filters so specifying all_tenants=0
or all_tenants=False when requesting a list of servers does not
result in instances from all tenants being returned.

Change-Id: I72575e4e2cf9019cfd5bf3b07ada53cadf2001e2
Closes-Bug: #1240347
Merge "all_tenants=0 should not return instances from all tenants"