Update git submodules

* Update helpcontent2 from branch 'master'
  to 6a31cba2f22a5a7cf60c1590b1189423fed285b3
  - (func_color.xhp) Include square brackets in syntax section to indicate optional parameter.
    
    Change-Id: I648260ba137015b29443944c983aac16f497b7d6
    Reviewed-on: https://gerrit.libreoffice.org/c/help/+/95207
    Tested-by: Jenkins
    Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>
    
diff --git a/helpcontent2 b/helpcontent2
index cae5dda..6a31cba 160000
--- a/helpcontent2
+++ b/helpcontent2
@@ -1 +1 @@
Subproject commit cae5dda033a7b19ecdb37a8abc571f31a5b798d4
Subproject commit 6a31cba2f22a5a7cf60c1590b1189423fed285b3