[xml/sgml-pkgs] Bug#611418: gnustep-base-common also fails with this

[Dave Steele]

Note that gnustep-base-common also fails on this directory:

    0m42.3s ERROR: FAIL: Package purging left files on system:
      /etc/xml	 owned by: xml-core, gnustep-base-common

gnustep-base-common is blocking 93 packages in Piuparts sid state
dependency-failed-testing, independent of those blocked by sgml-data
and docbook-xsl.