Update git submodules

* Update helpcontent2 from branch 'master'
  - Related: tdf#121173 double spaces
    
    Change-Id: I9e923e6e67393ed460b7641c5c478c00a2a36e0b
    Reviewed-on: https://gerrit.libreoffice.org/64888
    Tested-by: Jenkins
Reviewed-by: Sophie Gautier <gautier.sophie@gmail.com>
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>
    

helpcontent2 @ 3e81e4c5

-Subproject commit 21adf07053023db71838ecb833bd50ee700b079c
+Subproject commit 3e81e4c583e3db236891fc102c488d51583024fe