Fixed an issue when no weapon equipped.

diff --git a/DKCrutch.lua b/DKCrutch.lua
index e3570d2..4d75c4a 100755
--- a/DKCrutch.lua
+++ b/DKCrutch.lua
@@ -125,7 +125,7 @@ function DKCrutch.events.PLAYER_EQUIPMENT_CHANGED()

 	DKCrutch.hasT15_4pcs = DKCrutch:HasSetBonus( 138347, 4 );
 	_, itemSlot = GetInventorySlotInfo("MainHandSlot");
-	if (itemSlot) then
+	if (itemSlot) and (GetInventoryItemID("player", itemSlot)) then
 		_, _, _, _, _, _, _, _, itemType = GetItemInfo( GetInventoryItemID("player", itemSlot));
 		DKCrutch.dualWield = (itemType == "INVTYPE_WEAPON");
 	end