r/collectd-version: Auto-restart service

Sometimes, the `collectd-version` script crashes or fails to start at
boot.  Configuring systemd to automatically restart it will ensure that
it's always running, so machines' versions are consistently inventoried.

roles/collectd-version/files/collectd-version.service

@@ -2,10 +2,14 @@
 Description=collectd version plugin
 BindsTo=collectd.service
 After=collectd.service
+StartLimitInterval=1s
+StartLimitBurst=10
 
 [Service]
 ExecStart=/usr/local/libexec/collectd-version
 RemainAfterExit=true
+Restart=always
+RestartSec=500ms
 
 [Install]
 WantedBy=collectd.service