tests/test-gendoc-da.t

py3: enable legacy fs encoding to fix filename compatibility on Windows

This patch is untested. I just followed the instruction:

https://docs.python.org/3/whatsnew/3.6.html#pep-529-change-windows-filesystem-encoding-to-utf-8

#require docutils gettext

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