Comment 5 for bug 1580728

OK, the problem is the instance in this test has a unicode name:

http://git.openstack.org/cgit/openstack/tempest/tree/tempest/api/compute/servers/test_servers.py#n102

    @test.idempotent_id('5e6ccff8-349d-4852-a8b3-055df7988dd2')
    def test_update_server_name(self):
        # The server name should be changed to the provided value
        server = self.create_test_server(wait_until='ACTIVE')
        # Update instance name with non-ASCII characters
        prefix_name = u'\u00CD\u00F1st\u00E1\u00F1c\u00E9'
        self._update_server_name(server['id'], 'ACTIVE', prefix_name)