Update git submodules

* Update helpcontent2 from branch 'master'
  - remove empty paragraph, fixes a helpex warning
    
    Helpex warning: invalid po attributes extracted from /home/timar/libreoffice-master/helpcontent2/source/text/sbasic/python/python_shell.xhp
    No string specified!
    GroupID: N0120
    
    Change-Id: Ia3fa7d88f4756fd700eebcceb4480e0a553a5482
    

helpcontent2 @ 86716b10

-Subproject commit 925fcf8140657eeebf3d233cbe59323d856fe647
+Subproject commit 86716b1007ce47795e7e888908b540e034945172