Update git submodules

* Update helpcontent2 from branch 'master'
  - Use PRODUCTNAME from the configure.
    
    Change-Id: Ibc742e653f44093372bed4e103fedb3a597dfdac
    Reviewed-on: https://gerrit.libreoffice.org/58793Reviewed-by: Jan Holesovsky <kendy@collabora.com>
Tested-by: Jan Holesovsky <kendy@collabora.com>
    

helpcontent2 @ dbbcc7c9

-Subproject commit c86fd8dca6ed4def8305dbd3812c463e357b9f79
+Subproject commit dbbcc7c949167f4a88fa91373f3012e67e30d255