update repository scanning to remove DMI after Struts upgrade

git-svn-id: https://svn.apache.org/repos/asf/archiva/branches/archiva-1.3.x@1563510 13f79535-47bb-0310-9956-ffa450edef68
update repository group deletion so cancel works after Struts upgrade

git-svn-id: https://svn.apache.org/repos/asf/archiva/branches/archiva-1.3.x@1563511 13f79535-47bb-0310-9956-ffa450edef68