[OWL-1730][nqm-mng] Use `Ω`in the test of `Stop()`
[OWL-1730][nqm-mng] Use `Ω`in the test of `Stop()`

masato25/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,Cepave/open-falcon-backend,Cepave/open-falcon-backend,Cepave/open-falcon-backend