Make info_cache handle when network_info is None
Make info_cache handle when network_info is None

The info_cache['network_info'] data can be None, so don't string-
convert it to 'None'.

Related to blueprint unified-object-model

Change-Id: I7a18f9189ab31beca0f8df764531387b4dd41b50

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