Workaround for blank unlock dialog in kde with cairo-dock running

Just execute the following after cairo-dock is running:

xprop -root -remove RGB_DEFAULT_MAP

The following wrapper scripts takes care of it automatically:

#!/bin/sh
/usr/bin/cairo-dock &
sleep 5
xprop -root -remove RGB_DEFAULT_MAP

Sources:
http://bugreports.qt.nokia.com/browse/QTBUG-15092
https://bugs.kde.org/show_bug.cgi?id=262064