debian: put cache folder to install dirs of thruk

This fixes the following warning:
dpkg: warning: while removing naemon-core, directory '/var/cache/naemon' not empty so not removed.
while removing naemon-core.

Signed-off-by: Sven Nierlein <sven@consol.de>
bumped naemon-core and thruk

Signed-off-by: Sven Nierlein <sven@consol.de>