remove unused import
remove unused import

Change-Id: I71d3da8b3fcaaf9a521c5570afe92e508bf181b7

magic0704/python-keystoneclient,metacloud/python-keystoneclient,ntt-sic/python-keystoneclient,Mercador/python-keystoneclient,klmitch/python-keystoneclient,magic0704/python-keystoneclient,alexpilotti/python-keystoneclient,klmitch/python-keystoneclient,jamielennox/python-keystoneclient,jamielennox/python-keystoneclient,ntt-sic/python-keystoneclient,sdpp/python-keystoneclient,darren-wang/ksc,citrix-openstack-build/python-keystoneclient,jamielennox/python-keystoneclient,metacloud/python-keystoneclient,Mercador/python-keystoneclient,alexpilotti/python-keystoneclient,ging/python-keystoneclient,citrix-openstack-build/python-keystoneclient,ntt-sic/python-keystoneclient,citrix-openstack-build/python-keystoneclient,darren-wang/ksc,ging/python-keystoneclient,sdpp/python-keystoneclient