[ticket/12196] Revert Fix typo "referer" in acp/attachments

This reverts commit 9bc1f7924d5ef00fb988b81347d4c5c730b25eb2.
https://tracker.phpbb.com/browse/PHPBB3-12196

PHPBB3-12196
Merge pull request #2662 from dhruvgoel92/ticket/12196

[ticket/12196] Revert Fix typo "referer" in acp/attachments

* dhruvgoel92/ticket/12196:
  [ticket/12196] Revert Fix typo "referer" in acp/attachments