Fix warnings.filterwarnings call
Fix warnings.filterwarnings call

We need to use a keyword argument for the category since it is
not the second parameter to filterwarnings().

Change-Id: I0f393a742468c150e0debbc3453cf38ebc2fb58e

openstack-infra/shade,stackforge/python-openstacksdk,openstack/python-openstacksdk,dtroyer/python-openstacksdk,openstack-infra/shade,openstack/python-openstacksdk,dtroyer/python-openstacksdk,stackforge/python-openstacksdk