SPIGOT-665: Sticky pistons are moving pistons during the event

By: Thinkofdeath <thinkofdeath@spigotmc.org>

paper-api/src/main/java/org/bukkit/event/block/BlockPistonEvent.java

@@ -31,7 +31,7 @@ public abstract class BlockPistonEvent extends BlockEvent implements Cancellable
      * @return stickiness of the piston
      */
     public boolean isSticky() {
-        return block.getType() == Material.PISTON_STICKY_BASE;
+        return block.getType() == Material.PISTON_STICKY_BASE || block.getType() == Material.PISTON_MOVING_PIECE;
     }
 
     /**