fix: panic on empty leaderboards

src/main.rs

@@ -118,7 +118,7 @@ fn handle_hiscores(rx: mpsc::Receiver<(Entry, Leaderboard)>, hiscores_arc: Arc<M
 			Ok((new_entry,Leaderboard::Hiscores)) =>
 			{
 				let mut hiscores = hiscores_arc.lock().unwrap();
-				if new_entry.score > hiscores[19].score {
+				if hiscores.get(19).is_none_or(|hiscore| new_entry.score > hiscore.score) {
 					println!("New hiscore {new_entry:?}");
 					hiscores.push(new_entry);
 					hiscores.sort();
@@ -134,7 +134,7 @@ fn handle_hiscores(rx: mpsc::Receiver<(Entry, Leaderboard)>, hiscores_arc: Arc<M
 			Ok((new_entry,Leaderboard::Loscores)) =>
 			{
 				let mut loscores = loscores_arc.lock().unwrap();
-				if new_entry.score > loscores[19].score {
+				if loscores.get(19).is_none_or(|loscore| new_entry.score > loscore.score) {
 					println!("New loscore {new_entry:?}");
 					loscores.push(new_entry);
 					loscores.sort();