[main] Possible RESTManager.stop cleanup improvement

[qstokkink]

This was committed as part of #6206:

tribler/src/tribler-core/tribler_core/restapi/rest_manager.py

Lines 191 to 192 in e273b5c

	# Should the next line be used instead of the above lines?
	# await self.runner.cleanup()

In absence of a TODO here, I created this issue.

[qstokkink]

This code no longer exists and, therefore, this issue is no longer relevant.