contrib/systemd/labgrid-exporter: make service restart always and indefinitely

The exporter sets reexec=True for known errors only. If other errors
occur (e.g. network issues), the exporter exits with 0.

So set Restart=always to make sure even these exit conditions lead to a
restarted exporter. Drop the now redundant RestartForceExitStatus. Add
StartLimitIntervalSec=0 to make it restart indefinitely.

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Author: Bastian-Krause

contrib/systemd/labgrid-exporter.service

@@ -8,9 +8,9 @@ Environment="PYTHONUNBUFFERED=1"
 # Should contain LG_COORDINATOR configuration
 EnvironmentFile=-/etc/environment
 ExecStart=/path/to/labgrid/venv/bin/labgrid-exporter /etc/labgrid/exporter.yaml
-Restart=on-failure
-RestartForceExitStatus=100
+Restart=always
 RestartSec=30
+StartLimitIntervalSec=0
 DynamicUser=yes
 # Adjust to your distribution (most often "dialout" or "tty")
 SupplementaryGroups=dialout plugdev