Change l3build ID text so tests pass

As things stand, the tests now pass with the DocStripped version of
regression-test. For the present, do not change which version is used as there
is quite a bit in that file that is not in the new one.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@5041 de43f980-851b-0410-b2f7-c40aca1f87e0