Fix assertXPath in testcase for fdo#76098
Fix assertXPath in testcase for fdo#76098

Change xPath as suggested by Luke Deller in
https://gerrit.libreoffice.org/#/c/8572/.

Change-Id: Ibcf2bc6cd2b35df501aeeaf143a3928603cf6038

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core