powermanagement-interface: postrm script assumes ucf installed

[Trent Buck]

Package: powermanagement-interface
Version: 0.3.11
Severity: normal

When removing ubuntu-desktop (and its dependencies), this package's
postrm script fails because ucf has already been removed:

    /var/lib/dpkg/info/powermanagement-interface.postrm: 13: ucf: not found
    dpkg: error processing powermanagement-interface (--purge):
     subprocess post-removal script returned error exit status 127

-- System Information:
Debian Release: testing/unstable
  APT prefers edgy-updates
  APT policy: (500, 'edgy-updates'), (500, 'edgy-security'), (500, 'edgy')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/dash
Kernel: Linux 2.6.17-10-generic
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8)

Versions of packages powermanagement-interface depends on:
ii  acpi-support                  0.90       a collection of useful events for 

powermanagement-interface recommends no packages.

-- no debconf information