do not allow empty XML directory

src/rougail/xmlreflector.py

@@ -65,6 +65,8 @@ class XMLReflector:
             filenames = [join(xmlfolder, filename) for filename in listdir(xmlfolder) if \
                          filename.endswith('.xml')]
             filenames.sort()
+            if not filenames:
+                raise DictConsistencyError(_('there is no XML file'), 77, [xmlfolder])
             for xmlfile in filenames:
                 try:
                     document = parse(xmlfile)

tests/test_upgrade.py

@@ -54,7 +54,7 @@ def launch_test(test_dir):
     except Exception as err:
         # import traceback
         # traceback.print_exc()
-        print(f'cannot convert {test_dir}: {err}')
+        # print(f'cannot convert {test_dir}: {err}')
         rmtree(new_dest_dir)
         copytree(test_dir, new_dest_dir)
         return