"not enough arguments for format string" during batch ticket update

[khym@…]

I got this error when trying to do a batch update of tickets, with TimingAndEstimationPlugin 1.6.0b0 installed:

Traceback (most recent call last):
  File "c:\python27\lib\site-packages\trac\web\main.py", line 647, in _dispatch_request
    dispatcher.dispatch(req)
  File "c:\python27\lib\site-packages\trac\web\main.py", line 248, in dispatch
    resp = chosen_handler.process_request(req)
  File "c:\python27\lib\site-packages\trac\ticket\batch.py", line 72, in process_request
    new_values, comment, action)
  File "c:\python27\lib\site-packages\trac\ticket\batch.py", line 210, in _save_ticket_changes
    t.save_changes(req.authname, comment, when=when)
  File "c:\python27\lib\site-packages\trac\ticket\model.py", line 397, in save_changes
    listener.ticket_changed(self, comment, author, old_values)
  File "c:\python27\lib\site-packages\timingandestimationplugin-1.6.0b0-py2.7.egg\timingandestimationplugin\ticket_daemon.py", line 157, in ticket_changed
    self.watch_hours(ticket, author)
  File "c:\python27\lib\site-packages\timingandestimationplugin-1.6.0b0-py2.7.egg\timingandestimationplugin\ticket_daemon.py", line 126, in watch_hours
    self.log.debug("deleting ticket change %s %s %s %s" % tup)
TypeError: not enough arguments for format string

Looks like the problem is that tup has 3 elements​, but the format string expects 4. Removing one of the "%s"es fixes it.