msc_vlr_test_call: include RAN RTP addr in ass compl

I noticed by chance that the Assignment Complete message generated in
the test lacks a remote RTP address for the RAN side.

Make the test more realistic by adding a remote RTP address and port. It
doesn't have any bearing on the tests besides more accurately showing
RTP stream setup in the logs.

Change-Id: Ia428762a16dcc17f036d725a00e0b3767418289b
diff --git a/tests/msc_vlr/msc_vlr_tests.c b/tests/msc_vlr/msc_vlr_tests.c
index 3ef94f2..6b80452 100644
--- a/tests/msc_vlr/msc_vlr_tests.c
+++ b/tests/msc_vlr/msc_vlr_tests.c
@@ -1011,6 +1011,7 @@
 			.codec = assigned_codec,
 		},
 	};
+	osmo_sockaddr_str_from_str(&ran_dec.assignment_complete.remote_rtp, "1.2.3.4", 1234);
 	fake_msc_a_ran_dec(&ran_dec);
 
 	if (!conn_exists(g_msub))