feat(options1): update expected result

Expected result is updated to better showcase the difference between
- a valid result with no ice-creams `Some(0)`, and
- an invalid result `None`.

exercises/options/options1.rs

@@ -14,6 +14,7 @@ fn print_number(maybe_number: Option<u16>) {
 // TODO: Return an Option!
 fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // We use the 24-hour system here, so 10PM is a value of 22
+    // The Option output should gracefully handle cases where time_of_day > 24.
     ???
 }
 
@@ -24,8 +25,9 @@ mod tests {
     #[test]
     fn check_icecream() {
         assert_eq!(maybe_icecream(10), Some(5));
-        assert_eq!(maybe_icecream(23), None);
+        assert_eq!(maybe_icecream(23), Some(0));
-        assert_eq!(maybe_icecream(22), None);
+        assert_eq!(maybe_icecream(22), Some(0));
+        assert_eq!(maybe_icecream(25), None);
     }
 
     #[test]