Updated openstack/openstack
Project: openstack/taskflow  f333e1b2aacd8d5ed8efca76af6fc6d2e4535538

Remove rtype from task clone() doc

The sphinx docs don't seem to show this parameter
correctly when building the html docs so instead of
showing it just remove since the return type should
be pretty obvious due to the surronding text.

Change-Id: Id27c23d79d7fdbcd677ed959d9d817c796a0828c