[ticket/12909] Use correct lang vars in cli extension enable

PHPBB3-12909
Merge pull request #2793 from n-aleha/ticket/12909

[ticket/12909] Use correct lang vars in cli extension enable

* n-aleha/ticket/12909:
  [ticket/12909] Use correct lang vars in cli extension enable
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12909] Use correct lang vars in cli extension enable