Update git submodules

* Update helpcontent2 from branch 'master'
  - tdf#115254 Some branch bookmarks are not working 4
    
    sfx2 module dialogs
    
    Change-Id: Id7f799c0939c63695c29d0b6352e88c005386d3f
    Reviewed-on: https://gerrit.libreoffice.org/57468
    Tested-by: Jenkins
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>
    

helpcontent2 @ 6cd28b05

-Subproject commit d3b6ce0424e1aa359b297c63bbd16217a2e5b747
+Subproject commit 6cd28b0578beb4771c00b38f265870381045454e