patchdialog: Encode created patches to UTF-8

An alternative approach would be to reuse the encoding of the original
files. If we did that, we'd need to handle this better, including
adding a confirmation dialog and fallback. In the end, this is sane and
probably no one cares that much.

Author: kaiw

meld/patchdialog.py

@@ -118,6 +118,7 @@ def run(self):
                 filename = self.filediff._get_filename_for_saving(
                     _("Save Patch"))
                 if filename:
+                    txt = txt.encode('utf-8')
                     self.filediff._save_text_to_filename(filename, txt)
                     break