Fix windows build broken by #416

[lunny]

No description provided.

[bkcsoft]

I am not a huge fan of doing this... is there not another lib we can use?

[lunny]

Maybe endless? But I only used this one.

[appleboy]

@bkcsoft endless doesn't also support windows platform now. I do the same way in my gorush application.

for unix: /~https://github.com/appleboy/gorush/blob/v1.7.2/gorush/server_unix.go
for windows: /~https://github.com/appleboy/gorush/blob/v1.7.2/gorush/server_windows.go

LGTM 👍

[andreynering]

LGTM