fix error message when cannot validate ldap connection

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1448674 13f79535-47bb-0310-9956-ffa450edef68
fix compilation of mock RoleManager

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1448675 13f79535-47bb-0310-9956-ffa450edef68