Fix the host_get_all_by_queries() method
Fix the host_get_all_by_queries() method

Current logic misjudges that a ComputeHost object does not have an
attribute which is specified in a query if the value of the attribute
is 0 or False. This patch fixes the logic.

Change-Id: I9143f11dd022fe3f683c0f3a2a87c3f5562461d8

openstack/blazar,openstack/blazar,stackforge/blazar,stackforge/blazar,ChameleonCloud/blazar,ChameleonCloud/blazar