rpm: sync the shell version of triggers.systemd with the lua version

Note that this goes both ways: in particular the lua version had udev
scriptlets in the wrong package, fixed in
https://src.fedoraproject.org/rpms/systemd/c/3c9433d7cf4afc8d76660402f6c3d9d991596b83.

Add missing "|| :" so the scriptlets never fail.