tests/test-dirstate-nonnormalset.t

rcutil: don't check if defaultrc/ is a directory -- we know it is

`mercurial/defaultrc/` is a directory both in the Mercurial repo and
once installed on a target platform. The directory was created in
c4ce077588d0 (config: introduce "built-in" default configuration
settings in default.d, 2014-09-04). That commit has some more
information, but it still doesn't seem to say that `defaultrc/` (then
called `default.d/`) could be a file. Perhaps the check was there to
allow you to run the same code on an older install/repo?

Differential Revision: https://phab.mercurial-scm.org/D7624

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate="{rev}:{node|short} ({phase}) [{tags} {bookmarks}] {desc|firstline}\n"
  > [extensions]
  > dirstateparanoidcheck = $TESTDIR/../contrib/dirstatenonnormalcheck.py
  > [experimental]
  > nonnormalparanoidcheck = True
  > [devel]
  > all-warnings=True
  > EOF
  $ mkcommit() {
  >    echo "$1" > "$1"
  >    hg add "$1"
  >    hg ci -m "add $1"
  > }

  $ hg init testrepo
  $ cd testrepo
  $ mkcommit a
  $ mkcommit b
  $ mkcommit c
  $ hg status