Update git submodules

* Update helpcontent2 from branch 'master'
  - tdf#121532 Don't use non-standard `echo -n`
    
    At least the version of echo used to build TDF's LO 6.2.0.3 release apparently
    doesn't understand that non-standard option and printed out "-n" verbatim,
    generating a broken languages.js.  (Though my local macOS 10.14.3 /bin/echo does
    understand that option.)
    
    Change-Id: I7233fa5c6e7851c5086c428a67aaee71604061e1
    Reviewed-on: https://gerrit.libreoffice.org/67858
    Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
    

helpcontent2 @ 8986dec8

-Subproject commit 96e5f8c5059270f9d17b0151a90b6893eb3f433d
+Subproject commit 8986dec8229cf31ccfadb61e6e90c905f7033ac7