Stop using exception.message
Stop using exception.message

This usage has been deprecated since Python 2.6 and generates a warning
when running the code. Let's fix that in a way it is compatible for all
Python versions.

Change-Id: Ife404544f731ff098f4ce205da11bc452ed4d355

JianyuWang/nova,mikalstill/nova,klmitch/nova,alvarolopez/nova,tangfeixiong/nova,edulramirez/nova,adelina-t/nova,rahulunair/nova,takeshineshiro/nova,Yusuke1987/openstack_template,mandeepdhami/nova,klmitch/nova,tealover/nova,mikalstill/nova,gooddata/openstack-nova,bgxavier/nova,adelina-t/nova,dims/nova,noironetworks/nova,varunarya10/nova_test_latest,rajalokan/nova,MountainWei/nova,klmitch/nova,nikesh-mahalka/nova,joker946/nova,TwinkleChawla/nova,openstack/nova,petrutlucian94/nova,devendermishrajio/nova_test_latest,Tehsmash/nova,cloudbase/nova,j-carpentier/nova,alaski/nova,mandeepdhami/nova,openstack/nova,cernops/nova,Yusuke1987/openstack_template,jeffrey4l/nova,Stavitsky/nova,raildo/nova,ted-gould/nova,thomasem/nova,varunarya10/nova_test_latest,CloudServer/nova,blueboxgroup/nova,yatinkumbhare/openstack-nova,gooddata/openstack-nova,vmturbo/nova,CCI-MOC/nova,openstack/nova,JioCloud/nova,eonpatapon/nova,dawnpower/nova,kimjaejoong/nova,fnordahl/nova,tealover/nova,petrutlucian94/nova,mmnelemane/nova,cernops/nova,devendermishrajio/nova,zzicewind/nova,CloudServer/nova,watonyweng/nova,cyx1231st/nova,barnsnake351/nova,jianghuaw/nova,eonpatapon/nova,apporc/nova,Juniper/nova,felixma/nova,yatinkumbhare/openstack-nova,gooddata/openstack-nova,akash1808/nova_test_latest,bgxavier/nova,blueboxgroup/nova,akash1808/nova_test_latest,joker946/nova,cloudbase/nova,shail2810/nova,dawnpower/nova,iuliat/nova,rajalokan/nova,sebrandon1/nova,akash1808/nova,klmitch/nova,cyx1231st/nova,double12gzh/nova,devendermishrajio/nova_test_latest,yosshy/nova,Francis-Liu/animated-broccoli,watonyweng/nova,felixma/nova,JianyuWang/nova,rajalokan/nova,j-carpentier/nova,vmturbo/nova,belmiromoreira/nova,jianghuaw/nova,edulramirez/nova,vmturbo/nova,mahak/nova,TwinkleChawla/nova,gooddata/openstack-nova,NeCTAR-RC/nova,JioCloud/nova,hanlind/nova,nikesh-mahalka/nova,mikalstill/nova,mmnelemane/nova,phenoxim/nova,dims/nova,devendermishrajio/nova,mahak/nova,LoHChina/nova,alexandrucoman/vbox-nova-driver,BeyondTheClouds/nova,bigswitch/nova,zaina/nova,Juniper/nova,noironetworks/nova,fnordahl/nova,cernops/nova,zzicewind/nova,bigswitch/nova,CEG-FYP-OpenStack/scheduler,alvarolopez/nova,shail2810/nova,CEG-FYP-OpenStack/scheduler,takeshineshiro/nova,Juniper/nova,yosshy/nova,BeyondTheClouds/nova,tudorvio/nova,zaina/nova,isyippee/nova,rajalokan/nova,scripnichenko/nova,ted-gould/nova,cloudbase/nova,ruslanloman/nova,double12gzh/nova,rahulunair/nova,apporc/nova,rahulunair/nova,vmturbo/nova,JioCloud/nova_test_latest,Juniper/nova,kimjaejoong/nova,isyippee/nova,iuliat/nova,jianghuaw/nova,MountainWei/nova,Tehsmash/nova,mahak/nova,barnsnake351/nova,tangfeixiong/nova,whitepages/nova,thomasem/nova,sebrandon1/nova,jeffrey4l/nova,akash1808/nova,alaski/nova,raildo/nova,LoHChina/nova,alexandrucoman/vbox-nova-driver,ruslanloman/nova,Francis-Liu/animated-broccoli,BeyondTheClouds/nova,belmiromoreira/nova,CCI-MOC/nova,hanlind/nova,NeCTAR-RC/nova,jianghuaw/nova,whitepages/nova,sebrandon1/nova,phenoxim/nova,hanlind/nova,Stavitsky/nova,zhimin711/nova,JioCloud/nova_test_latest,tudorvio/nova,scripnichenko/nova,zhimin711/nova