close ClickUp Task when a Task is closed from Phabricator from a commit
NOTE: when Phabricator closes a Task from a commit message, the
related Webhook has type=NULL. This is probably nonsense. BTW
now we just ignore this type and we update the ClickUp Task.
This fixes a bug where the ClickUp was not closed, and then
after some time, the ClickUp webhook tries to re-open an
already closed Phabricator Task, previously closed from a commit.