[dev] ii missing include?

[Edgaras]

I was trying to compile ii against musl, and I found that it seems ii.c is
missing include declaration namely
#include <sys/select.h>
otherwise fd_set is undefined and most likely select() too. I do not know how
it compiles with gnu libc, or maybe this is problem with musl and select.h
should be included from some other header file, I do not know.