XXX some filter_type_dict does not exist with Libreoffice7

cloudooo/handler/ooo/mimemapper.py

@@ -147,6 +147,8 @@ class MimeMapper(object):
       ui_name = value.get('UIName')
       filter_type = value.get('Type')
       filter_type_dict = type_dict.get(filter_type)
+      if filter_type_dict is None:
+        continue
       if not ui_name:
         ui_name = filter_type_dict.get("UIName")
       if ui_name in ooo_disable_filter_name_list or 'Template' in ui_name: