[ticket/12456] Fix missing new lines at the end of email templates

PHPBB3-12456
[ticket/12456] Fix duplicated empty lines in language files

PHPBB3-12456
[ticket/12456] Add , after the last array element

PHPBB3-12456
Merge pull request #2364 from nickvergessen/ticket/12456

[ticket/12456] Missing new lines at the end of file in language files

* nickvergessen/ticket/12456:
  [ticket/12456] Add , after the last array element
  [ticket/12456] Fix duplicated empty lines in language files
  [ticket/12456] Fix missing new lines at the end of email templates
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12456] Add , after the last array element
  [ticket/12456] Fix duplicated empty lines in language files
  [ticket/12456] Fix missing new lines at the end of email templates