unreachable LDAP server blocks initialization for too long

Affected version

Version: 2.16.2

Summary

• Configure a combination with [GoodLDAP] or [BadLDAP]
• point BadLDAP to a ldapServer that times out (ldap://1.2.3.4/)
• Try to display the portal
• There is a timeout as Auth::LDAP and UserDB::LDAP preemptively try to connect to BadLDAP

Possible fixes

All Auth::LDAP and UserDB::LDAP methods validate the LDAP server before doing any work. So there is no need to try to connect in the init() method.