[web/calendar] fix regression in previous changeset "Enables css customization in CalendarView" was untested, and introduced a crash: TypeError: not all arguments converted during string formatting

#! /bin/sh -e

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