feat: replace systemctl commands with service equivalents

for sake of installing to devuan instead of debian, although the
latter should still work okay iiuc..

rattail_fabric2/collectd.py

@@ -59,7 +59,7 @@ def restart(c):
     """
     Restart the collectd service.
     """
-    c.sudo('systemctl restart collectd')
+    c.sudo("service collectd restart")
 
 
 def deploy_mountpoint_check_script(c, dest, **kwargs):