Don't error out when no item id could be parsed

diff --git a/BagSync.lua b/BagSync.lua
index 143b4c6..1a45d1c 100644
--- a/BagSync.lua
+++ b/BagSync.lua
@@ -846,7 +846,9 @@ local function AddItemToTooltip(frame, link) --workaround
 					end
 				end
 			end
-			link = select(2, GetItemInfo(newItemId)) -- replace original link with our found link
+			if newItemId then
+				link = select(2, GetItemInfo(newItemId)) -- replace original link with our found link
+			end
 		end
 	end