r12372: - make the periodic scheduling a bit easier, instead of passing

r12372: - make the periodic scheduling a bit easier, instead of passing
  an uint32_t next_interval everywhere, we now call wreplsrv_periodic_schedule()
  if we want to schedule an event
- also prevent us from looping with a 0 interval, by using 1s as minimum interval

metze
(This used to be commit b6943b11fc6e501d5081d591336185518943ee5a)