Ensure we don't end up with invalid exceptions again
Ensure we don't end up with invalid exceptions again

We've recently had a few (three?) exceptions where the messages
didn't work because there was a typo in the exception variable
name. This change adds a very simple unit test which ensures that
we don't end up in that state again.

Change-Id: I00423b4ce82428959e7591d5c5c47c1f25ec3029

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