读取excel的数据，FactorValue如果excel为空值就存null

performance/Performance.Services/PerExcelService/SheetDataRead/PerSheetDataReadIncome.cs

@@ -81,7 +81,7 @@ public List<IPerData> ReadData(ISheet sheet, List<PerHeader> perHeader)
                             CellValue = cellValue,
                             //Annotation = row.GetCell(athead.PointCell)?.CellComment?.String?.String,
                             UnitType = unit.UnitType, //手动匹配
-                            FactorValue = !string.IsNullOrEmpty(factorValue) ? ConvertHelper.ToDecimalOrNull(factorValue) : null,
+                            FactorValue =  ? ConvertHelper.ToDecimalOrNull(factorValue) : null,
                             IsFactor = true,
                         };
                         if (string.IsNullOrEmpty(data.AccountingUnit) && string.IsNullOrEmpty(data.Department))