tests/test-gendoc-da.t

test-phases-exchange: properly conditionalize output

I forgot to invert the conditions, and the test runner didn't catch it[1].  But
since only '&&' is supported in the per-line feature tests, this won't work
anyway.

[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-July/101941.html

#require docutils gettext

  $ $TESTDIR/check-gendoc da
  checking for parse errors