[etwist] clear ui cache at server startup time. Closes #1806933 this avoid pb when cubicweb/cubes provide new version of some js/css and also accumulating junk in the cache directories

#! /bin/sh -e

if [ -x "/etc/init.d/cubicweb-ctl" ]; then
    invoke-rc.d cubicweb-ctl restart || true
fi
 
 
#DEBHELPER#
 
exit 0