Fix Crash when Clicking on a non-slot with a stack in hand (#53)

* fix a crash when clicking in the gui with an item on anything that's not a slot,

* handle -1 slotid when quick moving

Author: ghzdude

src/main/java/com/cleanroommc/modularui/screen/ModularContainer.java

@@ -189,6 +189,9 @@ public boolean canInteractWith(@NotNull EntityPlayer playerIn) {
                 }
                 return inventoryplayer.getItemStack();
             }
+
+            if (slotId < 0) return ItemStack.EMPTY;
+
             if (clickTypeIn == ClickType.QUICK_MOVE) {
                 Slot fromSlot = getSlot(slotId);