Remove useless check on player interact cancellation (#5448)

This removes the BlockFlowerPot check that most likely was used when it was a tile entity.

Spigot-Server-Patches/Extend-Player-Interact-cancellation.patch

@@ -60,18 +60,6 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +                entityplayer.playerConnection.sendPacket(new PacketPlayOutCloseWindow());
 +            } else if (iblockdata.getBlock() instanceof BlockCommand) {
 +                entityplayer.playerConnection.sendPacket(new PacketPlayOutCloseWindow());
-+            } else if (iblockdata.getBlock() instanceof BlockFlowerPot) {
-+                // Send a block change to air and then send back the correct block, just to make the client happy
-+                PacketPlayOutBlockChange packet = new PacketPlayOutBlockChange(this.world, blockposition);
-+                packet.block = Blocks.AIR.getBlockData();
-+                this.player.playerConnection.sendPacket(packet);
-+
-+                this.player.playerConnection.sendPacket(new PacketPlayOutBlockChange(this.world, blockposition));
-+
-+                TileEntity tileentity = this.world.getTileEntity(blockposition);
-+                if (tileentity != null) {
-+                    player.playerConnection.sendPacket(tileentity.getUpdatePacket());
-+                }
              }
 +            // Paper end - extend Player Interact cancellation
              entityplayer.getBukkitEntity().updateInventory(); // SPIGOT-2867