Remove Classic Preference plugin because of breakages.

distro-packages/Slackware/doinst.sh

@@ -1,9 +0,0 @@
-if [ -x /usr/bin/update-desktop-database ]; then
-  /usr/bin/update-desktop-database -q usr/share/applications >/dev/null 2>&1
-fi
-
-if [ -e usr/share/icons/hicolor/icon-theme.cache ]; then
-  if [ -x /usr/bin/gtk-update-icon-cache ]; then
-    /usr/bin/gtk-update-icon-cache usr/share/icons/hicolor >/dev/null 2>&1
-  fi
-fi