Add osmo-gtphub systemd service file

Change-Id: I7ecfc9aa55611ae9975e5ef8c0716dae7598524c
diff --git a/contrib/systemd/osmo-gtphub.service b/contrib/systemd/osmo-gtphub.service
new file mode 100644
index 0000000..4881785
--- /dev/null
+++ b/contrib/systemd/osmo-gtphub.service
@@ -0,0 +1,12 @@
+[Unit]
+Description=Osmocom GTP Hub
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/osmo-gtphub -c /etc/osmocom/osmo-gtphub.cfg
+Restart=always
+RestartSec=2
+RestartPreventExitStatus=1
+
+[Install]
+WantedBy=multi-user.target