Flammable blocks adjacent to fire now burn away

There are some strange bugs with blockupdating causing invisible client-side-only fires that need to be investigated.

src/pocketmine/block/Block.php

@@ -534,6 +534,13 @@ class Block extends Position implements BlockIds, Metadatable{
 		return $this->getFlammability() > 0;
 	}
 
+	/**
+	 * Called when this block is burned away by being on fire.
+	 */
+	public function onIncinerate() : void{
+
+	}
+
 	/**
 	 * Returns the Block on the side $side, works like Vector3::getSide()
 	 *