Update to 2.8.1
    
    - Prevent also BackSpace from reopening a preedit when the option
      “Arrow keys can reopen a preedit” is off
    - Resolves: https://github.com/mike-fabian/ibus-typing-booster/issues/87
    - Resolves: rhbz#1637647
    - Translation updates from Weblate for es, tr, he
    - Update emoji annotations from CLDR