Update tests that can be broken with gettext-poison builds.

* nd/i18n-poison-test-updates:
  Fix tests under GETTEXT_POISON on parseopt
  Fix tests under GETTEXT_POISON on git-remote
  Fix tests under GETTEXT_POISON on pack-object
  Fix tests under GETTEXT_POISON on git-apply
  Fix tests under GETTEXT_POISON on diffstat
  Fix tests under GETTEXT_POISON on git-stash
  Fix tests under GETTEXT_POISON on relative dates