Update git submodules

* Update helpcontent2 from branch 'master'
  - update menu command to protect spreadsheet structure
    
    Change-Id: I14e424aea344ffeab47bc68d99b98dd56492dcbc
    Reviewed-on: https://gerrit.libreoffice.org/63521
    Tested-by: Jenkins
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>
    

helpcontent2 @ 789b9f58

-Subproject commit 33e5103fa682d5597b154bf952f543f1292171f7
+Subproject commit 789b9f58490c731c2497152be787130851977967