Description of problem:
When using %_preun_service in a spec file to remove a service in a package that I am working on, the following error occurs:-
#######################################

[root@jackodesktop baz]# urpme zoneminder
removing zoneminder-1.24.4-8.mga2.tainted.x86_64
process 26397: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3483.
This is normally a bug in some application using the D-Bus library.
  D-Bus not built with -rdynamic so unable to print a backtrace
/usr/share/rpm-helper/del-service: line 32: 26397 Aborted                 /bin/systemctl daemon-reload
removing package zoneminder-1.24.4-8.mga2.tainted.x86_64
writing /var/lib/rpm/installed-through-deps.list

#####################################

This appears to be caused by this section in /usr/share/rpm-helper/del-service.

    # support for systemd
    if [ -x /bin/systemctl ]; then
	    /bin/systemctl disable ${srv}.service > /dev/null 2>&1
	    /bin/systemctl daemon-reload
    fi

Commenting out the line "/bin/systemctl daemon-reload" removes the error.

Running that command in isolation reproduces the error.

NOTE. This is NOT the version of zoneminder in svn. The version in svn does NOT use rpm-helper so please don't use it to test ;)
The test version of zoneminder that is giving the error is available here:-

http://barjac-mtf.zapto.org/zoneminder-1.24.4-8.mga2.tainted.x86_64.rpm
http://barjac-mtf.zapto.org/zoneminder-1.24.4-8.mga2.tainted.src.rpm

If the problem is in the spec or init then my apologies, and any help will be appreciated ;)

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:

1. Install zoneminder using urpmi zoneminder-1.24.4-8.mga2.tainted.x86_64.rpm
2. Uninstall zoneminder using urpme zoneminder.
3. Errors during un-installation.