Revert "Only iterate over workers in workerstats if some are left in the worker_instances list"

This reverts commit 450f2040b2.

Of no advantage.

src/stratifier.c

@@ -3517,9 +3517,6 @@ static void *statsupdate(void *arg)
 			worker_instance_t *worker;
 			bool idle = false;
 
-			if (instance->workers < 1)
-				continue;
-
 			/* Decay times per worker */
 			DL_FOREACH(instance->worker_instances, worker) {
 				per_tdiff = tvdiff(&now, &worker->last_share);