fix collection for ProjectVersionMetadataModel

git-svn-id: https://svn.apache.org/repos/asf/archiva/sandbox/trunk@1491359 13f79535-47bb-0310-9956-ffa450edef68
fix typo which fix test :-)

git-svn-id: https://svn.apache.org/repos/asf/archiva/sandbox/trunk@1491360 13f79535-47bb-0310-9956-ffa450edef68