[ticket/8064] Change the collation of topic_first_poster_name

PHPBB3-8064
Merge remote-tracking branch 'github-nicofuma/ticket/8064' into develop-ascraeus

* github-nicofuma/ticket/8064:
  [ticket/8064] Change the collation of topic_first_poster_name
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/8064] Change the collation of topic_first_poster_name