SPIGOT-4836: Breaking barrier block causes error

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

paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java

@@ -446,8 +446,6 @@ public class CraftBlock implements Block {
             return new CraftBed(this);
         case CONDUIT:
             return new CraftConduit(this);
-        case BARRIER:
-            return new CraftBarrel(this);
         case BARREL:
             return new CraftBarrel(this);
         case BELL: