SPIGOT-4702: Exception when middle clicking certain slots

nms-patches/PlayerConnection.patch

@@ -1332,7 +1332,7 @@
 +                    case CLONE:
 +                        if (packetplayinwindowclick.d() == 2) {
 +                            click = ClickType.MIDDLE;
-+                            if (packetplayinwindowclick.c() == -999) {
++                            if (packetplayinwindowclick.c() < 0) {
 +                                action = InventoryAction.NOTHING;
 +                            } else {
 +                                Slot slot = this.player.activeContainer.getSlot(packetplayinwindowclick.c());