small fix in compute.x.id()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@1023 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
small fix in compute.x.id()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@1024 edb9625f-4e0d-4859-8d74-9fd3b1da38cb