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/arena/parkour/ParkourArena.java

@@ -253,7 +253,7 @@ public class ParkourArena implements Arena {
     @Override
     public boolean willCauseWin(Block block) {
         return (this.winLocation != null && this.winLocation.getBlock().equals(block)) ||
-                this.winBlockType == block.getType();
+                (this.winLocation == null && this.winBlockType == block.getType());
     }
 
     @Override