Update git submodules

* Update helpcontent2 from branch 'master'
  - tdf#121173 correct double spaces in sentences
    
    Change-Id: Ia8116e46e75cbf32293f20e0c905ed8707156b95
    Reviewed-on: https://gerrit.libreoffice.org/64886
    Tested-by: Jenkins
Reviewed-by: Sophie Gautier <gautier.sophie@gmail.com>
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>
    

helpcontent2 @ 911e28b1

-Subproject commit dc560c20cae5eb34c155ea65a34169cb19e830ca
+Subproject commit 911e28b1d83b4cb6bbac8c6c3ba7eb5d67d4a5f1