Fixes #4495: optimize LDAP requests for homepage infos
Merge pull request #446 from fanf/bug_4495/optimize_homepage_ldap_requests

Fixes #4495: optimize LDAP requests for homepage infos
Merge branch 'branches/rudder/2.6' of github.com:Normation/rudder into branches/rudder/2.8
Merge branch 'branches/rudder/2.8' into branches/rudder/2.9