msc: osmo-msc.cfg: move MGW params to 'mgw' node

This fixes deprecation warnings printed by recent osmo-msc.

Change-Id: I724ec44ea37bb61b457361befee3e6e92c886c0d
Related: osmo-mgw.git I95f717a0fcd3c4ca622e3989baa28fac1f7ec1ca
diff --git a/msc/osmo-msc.cfg b/msc/osmo-msc.cfg
index d05e400..a886565 100644
--- a/msc/osmo-msc.cfg
+++ b/msc/osmo-msc.cfg
@@ -57,11 +57,12 @@
  authentication optional
  rrlp mode none
  mm info 0
+ mgw 0
+  remote-ip 127.0.0.1
 msc
  assign-tmsi
  cs7-instance-a 0
  cs7-instance-iu 0
- mgw remote-ip 127.0.0.1
  emergency-call route-to-msisdn 112
  mncc external /tmp/mncc.sock
 mncc-int