fix unused import
fix unused import

fix unused import in nova/compute/manager.py

Change-Id: If5f9222365ed5814a6c288eb0507e6ba922cd4b4

TieWei/nova,apporc/nova,badock/nova,TwinkleChawla/nova,tudorvio/nova,gspilio/nova,belmiromoreira/nova,ntt-sic/nova,cyx1231st/nova,NeCTAR-RC/nova,shootstar/novatest,ewindisch/nova,alaski/nova,devendermishrajio/nova,redhat-openstack/nova,hanlind/nova,sridevikoushik31/openstack,aristanetworks/arista-ovs-nova,BeyondTheClouds/nova,houshengbo/nova_vmware_compute_driver,whitepages/nova,zaina/nova,cloudbase/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,ted-gould/nova,dims/nova,aristanetworks/arista-ovs-nova,thomasem/nova,felixma/nova,usc-isi/nova,CCI-MOC/nova,vmturbo/nova,jianghuaw/nova,luogangyi/bcec-nova,iuliat/nova,imsplitbit/nova,Stavitsky/nova,nikesh-mahalka/nova,SUSE-Cloud/nova,silenceli/nova,rajalokan/nova,gspilio/nova,scripnichenko/nova,plumgrid/plumgrid-nova,barnsnake351/nova,redhat-openstack/nova,maheshp/novatest,NeCTAR-RC/nova,OpenAcademy-OpenStack/nova-scheduler,devoid/nova,akash1808/nova_test_latest,affo/nova,silenceli/nova,JianyuWang/nova,petrutlucian94/nova_dev,adelina-t/nova,vmturbo/nova,klmitch/nova,watonyweng/nova,Juniper/nova,Yusuke1987/openstack_template,Juniper/nova,phenoxim/nova,shahar-stratoscale/nova,klmitch/nova,usc-isi/nova,edulramirez/nova,eonpatapon/nova,BeyondTheClouds/nova,MountainWei/nova,TieWei/nova,Francis-Liu/animated-broccoli,mikalstill/nova,Tehsmash/nova,adelina-t/nova,openstack/nova,jeffrey4l/nova,Triv90/Nova,bigswitch/nova,devendermishrajio/nova_test_latest,shahar-stratoscale/nova,alaski/nova,double12gzh/nova,dims/nova,maelnor/nova,houshengbo/nova_vmware_compute_driver,j-carpentier/nova,ted-gould/nova,tealover/nova,sridevikoushik31/nova,yosshy/nova,mgagne/nova,yatinkumbhare/openstack-nova,angdraug/nova,aristanetworks/arista-ovs-nova,klmitch/nova,houshengbo/nova_vmware_compute_driver,cloudbau/nova,tianweizhang/nova,nikesh-mahalka/nova,devendermishrajio/nova_test_latest,sridevikoushik31/nova,cyx1231st/nova,Stavitsky/nova,cernops/nova,zaina/nova,dstroppa/openstack-smartos-nova-grizzly,CiscoSystems/nova,saleemjaveds/https-github.com-openstack-nova,Metaswitch/calico-nova,TwinkleChawla/nova,sridevikoushik31/nova,raildo/nova,plumgrid/plumgrid-nova,ntt-sic/nova,joker946/nova,tealover/nova,yatinkumbhare/openstack-nova,leilihh/nova,Tehsmash/nova,alvarolopez/nova,bclau/nova,berrange/nova,alexandrucoman/vbox-nova-driver,vladikr/nova_drafts,rickerc/nova_audit,zhimin711/nova,SUSE-Cloud/nova,rickerc/nova_audit,jianghuaw/nova,fajoy/nova,double12gzh/nova,Yuriy-Leonov/nova,bgxavier/nova,CCI-MOC/nova,tianweizhang/nova,openstack/nova,blueboxgroup/nova,tangfeixiong/nova,sridevikoushik31/nova,noironetworks/nova,mahak/nova,cloudbau/nova,ewindisch/nova,bgxavier/nova,vmturbo/nova,watonyweng/nova,apporc/nova,whitepages/nova,jianghuaw/nova,gspilio/nova,viggates/nova,CloudServer/nova,JianyuWang/nova,rajalokan/nova,shail2810/nova,JioCloud/nova_test_latest,zzicewind/nova,citrix-openstack-build/nova,BeyondTheClouds/nova,sebrandon1/nova,fajoy/nova,affo/nova,luogangyi/bcec-nova,tangfeixiong/nova,vmturbo/nova,j-carpentier/nova,JioCloud/nova_test_latest,devendermishrajio/nova,fnordahl/nova,maelnor/nova,maoy/zknova,vladikr/nova_drafts,petrutlucian94/nova,ruslanloman/nova,Yusuke1987/openstack_template,phenoxim/nova,leilihh/novaha,sacharya/nova,tanglei528/nova,yosshy/nova,cernops/nova,iuliat/nova,CloudServer/nova,jeffrey4l/nova,takeshineshiro/nova,ruslanloman/nova,akash1808/nova,cloudbase/nova-virtualbox,dawnpower/nova,tudorvio/nova,joker946/nova,JioCloud/nova,sacharya/nova,maheshp/novatest,alexandrucoman/vbox-nova-driver,yrobla/nova,OpenAcademy-OpenStack/nova-scheduler,mahak/nova,Metaswitch/calico-nova,Yuriy-Leonov/nova,eayunstack/nova,spring-week-topos/nova-week,mmnelemane/nova,Triv90/Nova,shootstar/novatest,saleemjaveds/https-github.com-openstack-nova,rahulunair/nova,gooddata/openstack-nova,yrobla/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,usc-isi/nova,CEG-FYP-OpenStack/scheduler,hanlind/nova,akash1808/nova_test_latest,Juniper/nova,DirectXMan12/nova-hacking,badock/nova,fnordahl/nova,spring-week-topos/nova-week,orbitfp7/nova,klmitch/nova,maoy/zknova,raildo/nova,thomasem/nova,MountainWei/nova,Triv90/Nova,DirectXMan12/nova-hacking,mgagne/nova,berrange/nova,scripnichenko/nova,hanlind/nova,varunarya10/nova_test_latest,cernops/nova,dawnpower/nova,fajoy/nova,cloudbase/nova-virtualbox,varunarya10/nova_test_latest,mmnelemane/nova,leilihh/nova,leilihh/novaha,zzicewind/nova,noironetworks/nova,gooddata/openstack-nova,imsplitbit/nova,tanglei528/nova,mandeepdhami/nova,isyippee/nova,LoHChina/nova,projectcalico/calico-nova,sridevikoushik31/openstack,rajalokan/nova,CEG-FYP-OpenStack/scheduler,cloudbase/nova,LoHChina/nova,rrader/nova-docker-plugin,rajalokan/nova,virtualopensystems/nova,jianghuaw/nova,virtualopensystems/nova,orbitfp7/nova,citrix-openstack-build/nova,mandeepdhami/nova,petrutlucian94/nova_dev,openstack/nova,rrader/nova-docker-plugin,viggates/nova,barnsnake351/nova,eayunstack/nova,takeshineshiro/nova,sebrandon1/nova,sebrandon1/nova,Juniper/nova,projectcalico/calico-nova,JioCloud/nova,bclau/nova,mikalstill/nova,mahak/n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