Graceful restart by keeping currently playing entry, in case it matches the one to be scheduled
When Engine is crashing/restarting it normally (re-) schedules the entry which is planned per current timeslot. In case Engine Core didn't crash though, it successfully kept playing the planned timeslot-entry. In such case no new scheduling should happen i.e. when the playing entry is the one due to be scheduled.
Without the improvement, there is some Dead Air for some time, until the item is re-scheduled.