Fix error when subnet doesn't have a cidr set
Fix error when subnet doesn't have a cidr set

If it isn't set in the subnet just take it from the network_ref.

Change-Id: Id9b4a25b369884f4f4d5527b44d1215d3c244d70

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