r5123: fixed a bug in the timed events handling. It was possible for a timed

r5123: fixed a bug in the timed events handling. It was possible for a timed
event handler to trigger a free that could cause a timer to be
triggered twice. This changs fixes it properly by marking timer events
to be removed using a zero next_event time.

I also changed the default timeout for events.c to be infinite, so if
there are no events to handle then smbd will sit forever doing
nothing. That allows it to be swapped out completely when idle.
(This used to be commit 0f1fb7017ee441cbebcad45900435adb57ca1760)