Update git submodules

* Update helpcontent2 from branch 'master'
  to 42b1b45509ab2fa2de686f248781468e09d3f9d8
  - Use max-width in YouTube placeholder style
    
    Change-Id: I8acaa11f8d8c11f5034cea7c4dfc247cee90d487
    Reviewed-on: https://gerrit.libreoffice.org/c/help/+/129857
    Tested-by: Jenkins
    Reviewed-by: Ilmari Lauhakangas <ilmari.lauhakangas@libreoffice.org>
    
diff --git a/helpcontent2 b/helpcontent2
index 3994c9e..42b1b45 160000
--- a/helpcontent2
+++ b/helpcontent2
@@ -1 +1 @@
Subproject commit 3994c9e899323a85d4db4f9264f5dda8aae5b92b
Subproject commit 42b1b45509ab2fa2de686f248781468e09d3f9d8