If the operation isn't canceled it returns an error, printing this:

/libnm/client-nm-running:
(/home/dcbw/Development/fdo/NetworkManager/libnm/tests/.libs/lt-test-nm-client:17983): libnm-WARNING **: updated_properties: error reading NMRemoteSettings properties: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message did not receive a reply (timeout by message bus)
/bin/sh: line 5: 17983 Trace/breakpoint trap   ./libnm-test-launch.sh ${dir}$tst
FAIL: test-nm-client

which screws up testcases because they don't expect this message.
And in this case, since libnm knows that NM is exiting and will
just clear out the properties anyway, it's useless to print the message.