Update git submodules

* Update helpcontent2 from branch 'master'
  - Remove xml comments from file
    
    xml comments inside <bookmark> index are moved as is to Pootle
    and are not handled as comment when brought back to translated file.
    
    Change-Id: I040cf84851dea3feea26054cb9a0a20e1241c53b
    Reviewed-on: https://gerrit.libreoffice.org/73112
    Tested-by: Jenkins
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>
    

helpcontent2 @ eb191448

-Subproject commit 4a3888b8588facb3547bb2fcb995b0ab9220fa87
+Subproject commit eb191448f1af0dc6c3204f3fa626e9acb2d66fd2