better toString for debuging purpose

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-core/trunk@1430609 13f79535-47bb-0310-9956-ffa450edef68
this parameter is a String not Object

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-core/trunk@1430613 13f79535-47bb-0310-9956-ffa450edef68