[ticket/12837] Detect "viewing contact admin page" on viewonline

PHPBB3-12837
[ticket/12837] Use else if instead of elseif

PHPBB3-12837
Merge pull request #2741 from PayBas/ticket/12837

[ticket/12837] Detect "viewing contact admin page" on viewonline

* PayBas/ticket/12837:
  [ticket/12837] Use else if instead of elseif
  [ticket/12837] Detect "viewing contact admin page" on viewonline