I just needed the patch again and therefore committed and pushed it:

changeset:   4774:3adff0fb0207
user:        Thomas Arendsen Hein <thomas@intevation.de>
date:        Fri Mar 22 15:53:27 2013 +0100
files:       CHANGES.txt roundup/backends/back_sqlite.py
roundup/backends/rdbms_common.py
description:
Fixed issue2550595: Allow migrating from roundup 0.x to 1.4

All changes were required to make an upgrade from 0.6 to 1.4,
The changes affecting "retired" were required for an upgrade from 0.8 to
1.4.