Update git submodules

* Update helpcontent2 from branch 'master'
  - Related: tdf#121173 double spaces in sentences
    
    Change-Id: Id9e9094b932af787ceccbe5ea867459afe6677c0
    Reviewed-on: https://gerrit.libreoffice.org/64897
    Tested-by: Jenkins
Reviewed-by: Sophie Gautier <gautier.sophie@gmail.com>
Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>
    

helpcontent2 @ 6f928cff

-Subproject commit 793e75c7f7d321491e2eecfb88ed05f0661ffaf9
+Subproject commit 6f928cff923ffacc6a1e12b0ddb6b7938d7f463d