[ticket/12760] Fix wording for unapproved posts icon...

in last post column of forum lists.
https://tracker.phpbb.com/browse/PHPBB3-12760

PHPBB3-12760
Merge pull request #2649 from VSEphpbb/ticket/12760

[ticket/12760] Fix wording for unapproved posts icon...

* VSEphpbb/ticket/12760:
  [ticket/12760] Fix wording for unapproved posts icon...