This update for mailman fixes the following issues:

Security issue fixed:

- CVE-2018-13796: Fix a content spoofing vulnerability with invalid list name messages inside the web UI (boo#1101288).

Bug fixes:

- update to 2.1.29:
* Fixed the listinfo and admin overview pages that were broken

- update to 2.1.28:
* It is now possible to edit HTML and text templates via the web admin UI in a supported language other than the list's preferred_language.
* The Japanese translation has been updated
* The German translation has been updated
* The Esperanto translation has been updated
* The BLOCK_SPAMHAUS_LISTED_DBL_SUBSCRIBE feature added in 2.1.27 was not working. This is fixed.
* Escaping of HTML entities for the web UI is now done more selectively.