mgcp_client_test: also verify received conn_id

Include the parsed conn_id in the response cb printout to verify them in
mgcp_client_test.ok.

Change-Id: I6b9b18d4d0867febd75a4d29f8a2fcdf0553ae4c
diff --git a/tests/mgcp_client/mgcp_client_test.c b/tests/mgcp_client/mgcp_client_test.c
index 4e7e0a7..74ed53e 100644
--- a/tests/mgcp_client/mgcp_client_test.c
+++ b/tests/mgcp_client/mgcp_client_test.c
@@ -102,6 +102,7 @@
 	printf("response cb received:\n");
 	printf("  head.response_code = %d\n", response->head.response_code);
 	printf("  head.trans_id = %u\n", response->head.trans_id);
+	printf("  head.conn_id = %s\n", response->head.conn_id);
 	printf("  head.comment = %s\n", response->head.comment);
 	printf("  audio_port = %u\n", response->audio_port);
 	printf("  audio_ip = %s\n", response->audio_ip);