There's a problem on initial startup where sysinv-fpga-agent starts
up before sysinv.conf has the correct puppet server address, and
then doesn't get restarted once sysinv.conf is updated.
This creates a systemd entity that watches the sysinv.conf file
and any time the file is modified it triggers a restart of
sysinv-fpga-agent.
There may be a cleaner way to do this, but I was unable to find one.
Subscribing to the file in puppet didn't seem to work in my testing.
Change-Id: I367eeaad5ee8cfeb3536281d78f44cea284f3de6
Story: 2006740
Task: 39927
24273472e6