Install sample cfg file to /etc/osmocom

Change-Id: I19f3755f7637dfc017a89f503831f7df8098a919
diff --git a/debian/osmo-msc.install b/debian/osmo-msc.install
index 1e7f22f..e4b9646 100644
--- a/debian/osmo-msc.install
+++ b/debian/osmo-msc.install
@@ -1,3 +1,4 @@
+etc/osmocom/osmo-msc.cfg
 lib/systemd/system/osmo-msc.service
 usr/bin/osmo-msc
 usr/share/doc/osmo-msc/examples/osmo-msc/osmo-msc.cfg usr/share/doc/osmo-msc/examples