Remove unnecessary queries for network info in notifications
Remove unnecessary queries for network info in notifications

bandwidth_usage() tries to query network info if "not network_info"
when looking at instance['info_cache'].  [] is a valid entry for
network_info (on build)... so don't query network when we see it.

Fixes bug 1017770

Change-Id: Ia7291dbbcc25c04eff16eb048068f879e18f53a4

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