SPIGOT-6349: Material#MOSSY_COBBLESTONE incorrectly claims it is a MultipleFacing block

By: md_5 <git@md-5.net>

paper-api/src/main/java/org/bukkit/Material.java

@@ -506,10 +506,7 @@ public enum Material implements Keyed {
      */
     TNT(7896, TNT.class),
     BOOKSHELF(10069),
-    /**
+    MOSSY_COBBLESTONE(21900),
-     * BlockData: {@link MultipleFacing}
-     */
-    MOSSY_COBBLESTONE(21900, MultipleFacing.class),
     OBSIDIAN(32723),
     TORCH(6063),
     /**