[PATCH] Configure: don't test alternatives if preferred feature is found

[Piotr Sikora]

Hey Maxim,

> This looks like a mismerge, as previous tests is about
> IP_BIND_ADDRESS_NO_PORT (it is probably misplaced though).

Yeah, IP_BIND_ADDRESS_NO_PORT was added in the middle of
NGX_HAVE_TRANSPARENT_PROXY checks after I already wrote those changes
and I didn't catch the mis-merge.

Good catch, thanks!

Best regards,
Piotr Sikora