rewriteutil: replace "null changeset" by "the null revision" in error message The evolve extension uses "the null revision" and we seem to use that term much more frequently in core too. Differential Revision: https://phab.mercurial-scm.org/D10514

{
    "conduit_uri": "https://phab.mercurial-scm.org/api",
    "phabricator.uri": "https://phab.mercurial-scm.org/",
    "repository.callsign": "HG",
    "arc.land.onto.default": "@",
    "base": "hg:.^"
}