Redirection of /ldapadmin depending on roles

Fix https://github.com/georchestra/georchestra/issues/270

/ldapadmin/ is redirected to :
- /privateui/index.html if user is MOD_LDAPADMIN
- /account/userdetails if user is connected but not MOD_LDAPADMIN
- nowhere if not connected

Also fix https://github.com/georchestra/georchestra/issues/333