[ticket/12585] Don't check the cron on each page load

PHPBB3-12585
[ticket/12585] Use a 5 minutes interval instead of 10 minutes

PHPBB3-12585
Merge pull request #2490 from Nicofuma/ticket/12585

[ticket/12585] Don't check the cron on each page load

* Nicofuma/ticket/12585:
  [ticket/12585] Use a 5 minutes interval instead of 10 minutes
  [ticket/12585] Don't check the cron on each page load