Remove Upside down Seats

src/de/steamwar/spectatesystem/listener/PlayerSeatListener.java

@@ -20,6 +20,8 @@
 package de.steamwar.spectatesystem.listener;
 
 import org.bukkit.GameMode;
+import org.bukkit.block.data.Bisected;
+import org.bukkit.block.data.type.Stairs;
 import org.bukkit.entity.AbstractArrow;
 import org.bukkit.entity.Arrow;
 import org.bukkit.entity.EntityType;
@@ -41,6 +43,9 @@ public class PlayerSeatListener extends BasicListener {
         if(event.getPlayer().getGameMode() != GameMode.ADVENTURE)
             return;
 
+        if(((Stairs)event.getClickedBlock().getBlockData()).getHalf() != Bisected.Half.BOTTOM)
+            return;
+
         if(event.getPlayer().isInsideVehicle())
             event.getPlayer().getVehicle().remove();