Fixed issue where the aboveCell null check didn't work correctly as t…

…he check for col remaining was looking at rows instead.

src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/PdfPTable.cs

@@ -1362,7 +1362,7 @@ internal bool RowSpanAbove(int currRow, int currCol)
             {
                 int col = currCol - 1;
                 aboveCell = aboveRow.GetCells()[col];
-                while ((aboveCell == null) && (row > 0))
+                while ((aboveCell == null) && (col > 0))
                     aboveCell = aboveRow.GetCells()[--col];
                 return aboveCell != null && aboveCell.Rowspan > distance;
             }