Removed obsole part of scheduler that caused a crash

[spirali]

Fixes: #673

[Kobzol]

Great, even looks like a small perf. win on 10k-sleep:

Grouped by environment:
hq tag=current,worker_count=1,zero_worker=False
	sleep duration=0,task_count=10: 0.0621 s (min=0.0595, max=0.0648)
	sleep duration=0,task_count=100: 0.1659 s (min=0.1477, max=0.1840)
	sleep duration=0,task_count=1000: 0.5154 s (min=0.4969, max=0.5340)
	sleep duration=0,task_count=10000: 5.0719 s (min=5.0381, max=5.1057)
(mean): 1.4538 s

hq tag=main,worker_count=1,zero_worker=False
	sleep duration=0,task_count=10: 0.0508 s (min=0.0484, max=0.0532)
	sleep duration=0,task_count=100: 0.0982 s (min=0.0961, max=0.1003)
	sleep duration=0,task_count=1000: 0.5111 s (min=0.5029, max=0.5193)
	sleep duration=0,task_count=10000: 5.1543 s (min=5.0669, max=5.2417)
(mean): 1.4536 s

Left one nit.