Fixed problem with namespace prefix for sheetData tag in worksheet.

[Michael-Greiner]

EPPlus seems to have a problem, if the sheetData tag in a Worksheet has a XML namespace prefix:
After changing and saving the file, the Worksheet is empty.

How to reproduce the problem, using the attached file:

In Windows Powershell execute:

Add-Type -Path "C:\Users\xxx\Documents\Softwareentwicklung\libraries\EPPlus\EPPlus\EPPlus\bin\Debug\net40\EPPlus.dll"
$Path = "C:\Users\xxx\Desktop\PCC_definition_export_20190704133330_DE_EN.xlsx"
[OfficeOpenXml.ExcelPackage]$excelPackage = New-Object OfficeOpenXML.ExcelPackage($Path)
[OfficeOpenXml.ExcelWorkbook]$book = $excelPackage.Workbook
[OfficeOpenXml.ExcelWorksheet]$dataSheet = $book.Worksheets[1]
[OfficeOpenXml.ExcelRange]$cells = $dataSheet.Cells
$cells["A3"].Value # Display content of A3
$cells["A3"].Value = "asdf"
$excelPackage.SaveAs("$($Path)2.xlsx")

Problem: The saved file has an empty worksheet :-(

How I fixed the problem:
Just remove the namespace prefix.
Why would you use a namespace prefix for the document wide namespace anyway? :-)

PCC_definition_export_20190704133330_DE_EN.xlsx