Bug#670982: fontconfig-config: fail to delete non-empty /var/lib/defoma/fontconfig.d/

Package: fontconfig-config
Version: 2.9.0-2
Severity: important

in latest post-install script included such lines

DEFOMA=/var/lib/defoma/fontconfig.d/
if [ -d $DEFOMA ]; then
    rm -f $DEFOMA/fonts.conf
    rmdir $DEFOMA
fi

but this directory also contains file id-cache, so installation fails

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing-proposed-updates
  APT policy: (500, 'testing-proposed-updates'), (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-2-amd64 (SMP w/2 CPU cores)
Locale: LANG=ru_RU.UTF-8, LC_CTYPE=ru_RU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages fontconfig-config depends on:
ii  debconf [debconf-2.0]  1.5.42
ii  gsfonts-x11            0.22
ii  ttf-dejavu-core        2.33-2
ii  ttf-freefont           20100919-1
ii  ucf                    3.0025+nmu3

fontconfig-config recommends no packages.

fontconfig-config suggests no packages.

-- debconf information:
  fontconfig/subpixel_rendering: Automatic
  fontconfig/enable_bitmaps: false
  fontconfig/hinting_type: Native