title: Gitlab login LDAP user without e-mail
body: <p>In my organization, some users don't have an e-mail address. At the e-mail field in ActiveDirectory, they have a fake (malformed) e-mail address, something like "user.name@xx".</p>
  
  <p>When these users try to login into Gitlab, they get the following error:</p>
  
  <p>'Could not authorize you from LDAP because "Validation failed: email is invalid, email is invalid".'</p>
  
  <p>Is there any configuration to ignore email adress checking with LDAP?</p>