[ticket/10521] Fix broken tests using set_cookie

PHPBB3-10521
Merge remote-tracking branch 'VSEphpbb/ticket/10521' into develop-ascraeus

* VSEphpbb/ticket/10521:
  [ticket/10521] Fix broken tests using set_cookie
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/10521] Fix broken tests using set_cookie