Fix init scripts for shitstemd units, as in #875696 but now Closes #979545 for unit files

added changelog entry but do not released, wait for DD mantainer `Closes: #979545, #979161

The (again) s(h)ystemd does not allow a good installation of mlm cos package will fail to install with error "Missing LISTS setting" becouse the webmlmrc file does not have yet defined at postinstall step

In old days of the good sysvinit the package have a "default" file at /etc/defaults that said to not run yet the daemon and of course does not faill with init scripts