Print friendly message if no floating IPs exist.
Print friendly message if no floating IPs exist.

Fix bug 932071.

Print out a friendly message from nova-manage when the "floating list"
command is issued but no floating IPs have been defined.  Prior to this
change, a generic error message would be printed, pointing to the log
for further details.

Change-Id: I0d11f93e9f51cf4e99e319bc9296f73380564257

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