Set a more reasonable default RPC thread pool size
Set a more reasonable default RPC thread pool size

No service should be doing over 1000 different tasks at once. It can
only possibly end up overloading other dependent services. 64 should
be a more reasonable starting point.

Change-Id: I7690ad4a9cfc5ee11e1990d5cecdf23522f11f72

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