fix patrole-multinode-member non-voting gate by skip_because a bug

the bug is due to a nova api that is allowed with a system scoped
token and patrole does not support them at this time.

https://storyboard.openstack.org/#!/story/2008051
Closes-Bug:2008051

Change-Id: I6963fdff199fca342620ab15948ce2c1d29c2c7a
diff --git a/patrole_tempest_plugin/tests/api/compute/test_server_volume_attachments_rbac.py b/patrole_tempest_plugin/tests/api/compute/test_server_volume_attachments_rbac.py
index 74f8110..946bf3f 100644
--- a/patrole_tempest_plugin/tests/api/compute/test_server_volume_attachments_rbac.py
+++ b/patrole_tempest_plugin/tests/api/compute/test_server_volume_attachments_rbac.py
@@ -179,6 +179,7 @@
             self.servers_client.show_volume_attachment(
                 self.server['id'], attachment['id'])
 
+    @decorators.skip_because(bug='2008051', bug_type='storyboard')
     @decorators.attr(type='slow')
     @testtools.skipUnless(CONF.compute_feature_enabled.swap_volume,
                           'In-place swapping of volumes not supported.')