Fix the numbers displayed for screen width.

testdoor/testdoor.go

@@ -376,7 +376,7 @@ func width_demo(d *door.Door) {
 		if y%10 == 0 {
 			line = strings.Repeat("1234567890", w/10)
 			for x := len(line); x < w; x++ {
-				line += strconv.Itoa(x % 10)
+				line += strconv.Itoa((x + 1) % 10)
 			}
 		} else {
 			line = ""