Merge pull request #3383 from yj2317916/patch-1

need region param

lib/fog/openstack/volume.rb

@@ -193,6 +193,7 @@ module Fog
               :openstack_api_key  => @openstack_api_key,
               :openstack_username => @openstack_username,
               :openstack_auth_uri => @openstack_auth_uri,
+              :openstack_region   => @openstack_region,
               :openstack_auth_token => @openstack_must_reauthenticate ? nil : @openstack_auth_token,
               :openstack_service_type => @openstack_service_type,
               :openstack_service_name => @openstack_service_name,