Switch capability_scope to global
Switch capability_scope to global

- In multi-host scenario, kuryr-libnetwork capability_scope conf should be
  global.
- The Zun multinode gate failed because of KuryrException [1]. Turn debug mode
  on to get more information.

[1]
http://logs.openstack.org/11/494111/10/experimental/gate-tempest-dsvm-zun-multinode-docker-sql-ubuntu-xenial-nv/3e1c24e/logs/screen-kuryr-libnetwork.txt.gz#_Aug_17_08_58_04_196174

Change-Id: Ic1fc0b984929b3c13201fcc9f723a91e81234f3e

openstack-infra/project-config,openstack-infra/project-config