parser: a small immutable field fix

vlib/os/os_nix.v

@@ -9,7 +9,7 @@ const (
 
 fn init_os_args(argc int, argv &byteptr) []string {
 	mut args := []string
-	for i := 0; i < argc; i++ {
+	for i in 0 .. argc {
 		args << string(argv[i])
 	}		
 	return args