[ticket/12854] Don't show contact page link if board emails are disabled

PHPBB3-12854
Merge pull request #2736 from Elsensee/ticket/12854

[ticket/12854] Don't show contact page link if board emails are disabled

* Elsensee/ticket/12854:
  [ticket/12854] Don't show contact page link if board emails are disabled
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12854] Don't show contact page link if board emails are disabled