Bumps [phpoffice/phpspreadsheet](https://github.com/PHPOffice/PhpSpreadsheet) from 1.4.0 to 1.8.0.
- [Release notes](https://github.com/PHPOffice/PhpSpreadsheet/releases)
- [Changelog](https://github.com/PHPOffice/PhpSpreadsheet/blob/master/CHANGELOG.PHPExcel.md)
- [Commits](https://github.com/PHPOffice/PhpSpreadsheet/compare/1.4.0...1.8.0

)

Signed-off-by: dependabot[bot] <support@github.com>

26535 - Column 'virtual' is a reserved word in mysql >=5.7

fixed worng background image pathes

hotfix: column 'virtual' is a reserved word in mysql >=5.7 and leads to database exception. The hotfix replaces all ->manipulate calls with corresponding ->insert/update calls which quotes column identifier automatically

fixed too early web dir replacement

[FIX] 0026414: Dateilisten im Lernmodul , simples einfügen 1 Datei schreibt in U-Ordner 002, auch bei Initialer Version.

SAML: Replace continue; With break; In Switch Statement

fixed mantis 0026238: Keine druckbaren Antworten im Ergebnisse-Tab (PART 2 - access handling for regular users)