Comment 9 for bug 1271713

This bug was fixed in the package xfdesktop4 - 4.11.4-1ubuntu1.

From the xfdesktop 4.11.4 changelog:
* Better migration from previous versions:
  - Xfdesktop now does a better job of migrating any user settings
    from 4.10 and before to the new xfconf properties.
  - Fix an settings issue when plug names aren't available