Remove #include <unistd.h>. Not portable to NT and is apparently

not needed for any unix-standard thing, at least none that I could
identify in the file, and removing it did not generate any errors
on BSD/OS.

lib/isc/sockaddr.c

@@ -20,7 +20,6 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
 #include <stdio.h>
 
 #include <isc/types.h>