NIST: increase RSA key length to 2048 bit
NIST: increase RSA key length to 2048 bit

According to NIST 800-131A, RSA key lenght for digital signature
must >= 2048 bit. Now we use 1024 bit key to generate x509 cert
file. Need to increase the key length to 2048 bit.

Change-Id: I59f614b5d8a79f9e0a96503867cfca176be5c757
Closes-Bug: 1369487

rajalokan/nova,j-carpentier/nova,blueboxgroup/nova,affo/nova,raildo/nova,petrutlucian94/nova,belmiromoreira/nova,belmiromoreira/nova,silenceli/nova,redhat-openstack/nova,bigswitch/nova,orbitfp7/nova,zzicewind/nova,cloudbase/nova,MountainWei/nova,joker946/nova,devendermishrajio/nova,akash1808/nova_test_latest,adelina-t/nova,dims/nova,whitepages/nova,JioCloud/nova_test_latest,tianweizhang/nova,raildo/nova,CCI-MOC/nova,whitepages/nova,ted-gould/nova,CCI-MOC/nova,jeffrey4l/nova,tudorvio/nova,angdraug/nova,zzicewind/nova,Yusuke1987/openstack_template,tealover/nova,rajalokan/nova,zhimin711/nova,Juniper/nova,shail2810/nova,vmturbo/nova,isyippee/nova,alexandrucoman/vbox-nova-driver,mikalstill/nova,noironetworks/nova,yatinkumbhare/openstack-nova,jianghuaw/nova,berrange/nova,Juniper/nova,iuliat/nova,Juniper/nova,jianghuaw/nova,cernops/nova,vmturbo/nova,iuliat/nova,shail2810/nova,rajalokan/nova,berrange/nova,angdraug/nova,sebrandon1/nova,Tehsmash/nova,cloudbase/nova,Juniper/nova,mikalstill/nova,badock/nova,Metaswitch/calico-nova,openstack/nova,MountainWei/nova,klmitch/nova,JioCloud/nova,LoHChina/nova,bigswitch/nova,apporc/nova,cloudbase/nova-virtualbox,gooddata/openstack-nova,felixma/nova,cloudbase/nova,mmnelemane/nova,projectcalico/calico-nova,openstack/nova,BeyondTheClouds/nova,gooddata/openstack-nova,ruslanloman/nova,dawnpower/nova,JianyuWang/nova,Francis-Liu/animated-broccoli,alaski/nova,tangfeixiong/nova,barnsnake351/nova,nikesh-mahalka/nova,alvarolopez/nova,fnordahl/nova,barnsnake351/nova,tudorvio/nova,Yusuke1987/openstack_template,mgagne/nova,CEG-FYP-OpenStack/scheduler,jeffrey4l/nova,dawnpower/nova,zhimin711/nova,klmitch/nova,devendermishrajio/nova_test_latest,cernops/nova,varunarya10/nova_test_latest,mahak/nova,BeyondTheClouds/nova,TwinkleChawla/nova,watonyweng/nova,mahak/nova,gooddata/openstack-nova,mikalstill/nova,edulramirez/nova,mandeepdhami/nova,eonpatapon/nova,TwinkleChawla/nova,apporc/nova,bgxavier/nova,adelina-t/nova,hanlind/nova,sebrandon1/nova,vmturbo/nova,gooddata/openstack-nova,tealover/nova,cyx1231st/nova,eonpatapon/nova,maelnor/nova,silenceli/nova,nikesh-mahalka/nova,mmnelemane/nova,zaina/nova,redhat-openstack/nova,joker946/nova,rahulunair/nova,JianyuWang/nova,badock/nova,tianweizhang/nova,NeCTAR-RC/nova,yosshy/nova,JioCloud/nova_test_latest,scripnichenko/nova,blueboxgroup/nova,kimjaejoong/nova,rahulunair/nova,mahak/nova,devendermishrajio/nova_test_latest,cyx1231st/nova,thomasem/nova,j-carpentier/nova,alexandrucoman/vbox-nova-driver,isyippee/nova,phenoxim/nova,sebrandon1/nova,fnordahl/nova,eayunstack/nova,rahulunair/nova,akash1808/nova_test_latest,cernops/nova,jianghuaw/nova,bgxavier/nova,maelnor/nova,double12gzh/nova,scripnichenko/nova,phenoxim/nova,yosshy/nova,thomasem/nova,mgagne/nova,openstack/nova,cloudbase/nova-virtualbox,yatinkumbhare/openstack-nova,devendermishrajio/nova,takeshineshiro/nova,zaina/nova,alaski/nova,JioCloud/nova,Metaswitch/calico-nova,BeyondTheClouds/nova,double12gzh/nova,kimjaejoong/nova,ruslanloman/nova,Stavitsky/nova,edulramirez/nova,Francis-Liu/animated-broccoli,NeCTAR-RC/nova,akash1808/nova,hanlind/nova,ted-gould/nova,CloudServer/nova,varunarya10/nova_test_latest,dims/nova,affo/nova,jianghuaw/nova,klmitch/nova,rajalokan/nova,petrutlucian94/nova,LoHChina/nova,projectcalico/calico-nova,felixma/nova,alvarolopez/nova,Stavitsky/nova,CEG-FYP-OpenStack/scheduler,mandeepdhami/nova,Tehsmash/nova,takeshineshiro/nova,eayunstack/nova,vmturbo/nova,klmitch/nova,watonyweng/nova,noironetworks/nova,tangfeixiong/nova,orbitfp7/nova,hanlind/nova,akash1808/nova,CloudServer/nova