CHUI-881 ([CHUIBUG]Viewer crashes when user drag and drop the participant from...

CHUI-881 ([CHUIBUG]Viewer crashes when user drag and drop the participant from the people floater to the one of the tool bars): Problem was that the item dragged from the people list was not of type inventoryitem. Instead of casting to an inventoryitem and checking if the item being dragged is a widgit, instead look at the cargo type (which also specifies that the dragged item is a widgit but doesn't need to typecast).

indra/llui/lltoolbar.cpp

@@ -1059,10 +1059,9 @@ BOOL LLToolBar::handleDragAndDrop(S32 x, S32 y, MASK mask, BOOL drop,
 	// Convert drag position into insert position and rank 
 	if (!isReadOnly() && handled && !drop)
 	{
-		LLInventoryItem* inv_item = (LLInventoryItem*)cargo_data;
-		LLAssetType::EType type = inv_item->getType();
-		if (type == LLAssetType::AT_WIDGET)
+		if (cargo_type == DAD_WIDGET)
 		{
+			LLInventoryItem* inv_item = (LLInventoryItem*)cargo_data;
 			LLCommandId dragged_command(inv_item->getUUID());
 			int orig_rank = getRankFromPosition(dragged_command);
 			mDragRank = getRankFromPosition(x, y);