I just upgraded my charm which wrote a new proxy-server.conf (with changes) but the charm did not restart the swift-proxy service as a result:
root@juju-8d95f0-swift-3:~# ll /etc/swift/proxy-server.conf
-rw-r--r-- 1 root root 2172 Jun 6 14:26 /etc/swift/proxy-server.conf
root@juju-8d95f0-swift-3:~# date
Wed Jun 6 14:30:26 UTC 2018
root@juju-8d95f0-swift-3:~# ps -e -opid,etime,cmd| grep swift
6056 00:16 python3 /var/lib/juju/agents/unit-swift-proxy-0/charm/hooks/update-status
6389 00:00 grep --color=auto swift
12294 52:06 bash /var/lib/juju/init/jujud-unit-swift-proxy-0/exec-start.sh
12304 52:06 /var/lib/juju/tools/unit-swift-proxy-0/jujud unit --data-dir /var/lib/juju --unit-name swift-proxy/0 --debug
31326 38:46 /usr/bin/python /usr/bin/swift-proxy-server /etc/swift/proxy-server.conf
31338 38:44 /usr/bin/python /usr/bin/swift-proxy-server /etc/swift/proxy-server.conf
I haven't been able to reproduce this and config-changed appears to have the correct restart decorator. Can you confirm that this bug is still occurring please?