Only enforce valid uuids if a uuid is passed.
Only enforce valid uuids if a uuid is passed.

This fixes bug 1029721 which was causing instance spawn failures.

Change-Id: Iab7fdb063874972e0bcd91c51bfd0e5b49e8023c

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