Indeed, it's unnecessary in my dev environment, but I just added it for if someone was building with an older toolchain, although such a toolchain might fail to get HAVE_GETADDRINFO_A defined by configure script at the first place, but just in case.

Sure it should be pretty safe to remove the macro definition check, I'd like to do that if you think that is desired, but it could be even safer (ok, quite little) to leave it there:)