Do not request blank LDAP attributes.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2056 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/auth_source_ldap.rb

@@ -91,6 +91,8 @@ class AuthSourceLdap < AuthSource
   end
   
   def self.get_attr(entry, attr_name)
-    entry[attr_name].is_a?(Array) ? entry[attr_name].first : entry[attr_name]
+    if !attr_name.blank?
+      entry[attr_name].is_a?(Array) ? entry[attr_name].first : entry[attr_name]
+    end
   end
 end