[ticket/9975] Translate missing style error message

The error message about missing style data was not
translated

PHPBB3-9975
Merge pull request #1358 from MGaetan89/ticket/9975

[ticket/9975] Translate missing style error message
[ticket/11517] Fix list numbering

PHPBB3-11517
Merge remote-tracking branch 'hjpotter92/ticket/11517' into develop-olympus

* hjpotter92/ticket/11517:
  [ticket/11517] Fix list numbering