I have set up my tezos services to be controlled by systemd using etomknudsen's scripts. The output from those services gets logged by journald with double timestamps since both the tezos applications and journald itself each add a timestamp. For tezos-node a typical log line looks like this:
Mar 18 08:44:58 baker.example.com tezos-node[27442]: Mar 18 08:44:58 - validator.chain(1): Pushed: 2019-03-18T13:44:58Z, Treated: 2019-03-18T13:44:58Z, Completed: 2019-03-18T13:44:58Z
Can I change the configuration so that only one timestamp appears in each log line?