base-revsets: use an author that actually exercises a lot of changesets
This was caught in my big find-and-replace: d4ba4d51f85f.
The point of `base-revsets` is to give revsets that will give a good coverage
of the repository. Using Pierre-Yves as the second largest committer
(in terms of number of changesets) seems like a good idea.
$ LANG=nonexistent LC_ALL=nonexistent LANGUAGE=nonexistent hg version -q
Mercurial Distributed SCM (version *) (glob)