this header should not be included on windows

src/getopt.c

@@ -33,7 +33,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
+#ifndef _WIN32
+# include <unistd.h>
+#endif
 
 int	opterr = 1,		/* if error message should be printed */
 	optind = 1,		/* index into parent argv vector */