fix osmo-smlc.service: drop unknown '-s' command line argument

Change-Id: I3804fea29e06280f12b62e8c27d2a0ba4aafa7a0
diff --git a/contrib/systemd/osmo-smlc.service b/contrib/systemd/osmo-smlc.service
index 23a8f86..e159370 100644
--- a/contrib/systemd/osmo-smlc.service
+++ b/contrib/systemd/osmo-smlc.service
@@ -4,7 +4,7 @@
 [Service]
 Type=simple
 Restart=always
-ExecStart=/usr/bin/osmo-smlc -c /etc/osmocom/osmo-smlc.cfg -s
+ExecStart=/usr/bin/osmo-smlc -c /etc/osmocom/osmo-smlc.cfg
 RestartSec=2
 
 [Install]