Fixes some bugs

Fixes the win block type causing a win even when the win location is set.
Fixes the leave command only working for dropper arenas.
Fixes the command listener only cancelling command usage while in a dropper arena.
Fixes only dropper sessions being quit when the server stops.

src/main/java/net/knarcraft/minigames/MiniGames.java

@@ -279,7 +279,7 @@ public final class MiniGames extends JavaPlugin {
     public void onDisable() {
         // Throw out currently playing players before exiting
         for (Player player : getServer().getOnlinePlayers()) {
-            DropperArenaSession session = dropperArenaPlayerRegistry.getArenaSession(player.getUniqueId());
+            ArenaSession session = getSession(player.getUniqueId());
             if (session != null) {
                 session.triggerQuit(true);
             }