[ticket/12814] Replace email type with text type

PHPBB3-12814
Merge pull request #2735 from carlo94it/ticket/12814

[ticket/12814] Fix field type for LDAP email attribute

* carlo94it/ticket/12814:
  [ticket/12814] Replace email type with text type
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12814] Replace email type with text type