#134 Extend ldap search filter

[Joerg Dorchain]

I find it convinient to type in parts of mailadresses,
not just names, in the search field.

replacing line 252 in abook_ldap_server.php with
$expression = "(|(cn=$expr)(mail=$expr)(sn=$expr))";

does it the same way as e.g. thunderbird or outlook.

I'd be happy if you would apply this simple pseudo patch.