Update git submodules

* Update helpcontent2 from branch 'master'
  - Help files: http -> https
    
    + some more conservative changes
    
    Change-Id: I7b4bffc78fce6fe764a1746c060a403cb1b934eb
    Reviewed-on: https://gerrit.libreoffice.org/63217
    Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
    

helpcontent2 @ ab5c2340

-Subproject commit 7edbeb56b088685f4b88c6d4300a3c145c2faf58
+Subproject commit ab5c2340fcb35813db7777460fe851ae5b49c9b3