Find wrong results for ports opened by shadowsocks-libev on Mac

[Eggham]

I used shadowsocks-libev opened a few tcp ports on my Mac. The ports being used by shadowsocks-libev car shown by the operating system, but Portastic still reports that these ports are free for use. An example of debug info is as follows. Note port 4002 has been used by shadowsocks-libev.

portastic:test Trying to test port 4002 +0ms portastic:test TCP server on port 4002 closed +4ms portastic:test Port 4002 was free +0ms

It is worth to mention that ports used by other programs are correctly detected by Portastic.