client: do not start connections in loopback mode

Starting connections in loopback bode may cause confusion at the
receiving end when the connection is switched from looback into
an actual send-receive connection. The reason for this is by this
the SSRC of the RTP stream will suddenly change. For the majority
of usecases it is not necessary to loopback the incomming packets
back to the receiver in the beginning. So lets use receive-only
as a safe default.

- use MGCP_CONN_RECV_ONLY instead of MGCP_CONN_RECV_LOOPBACK

Change-Id: I44178434ee497bc1d5e9d5f6d92c13c1a09ae241
Related: OS#3104

src/libosmo-mgcp-client/mgcp_client_fsm.c

@@ -112,7 +112,7 @@ static struct msgb *make_crcx_msg_bind(struct mgcp_ctx *mgcp_ctx)
 		.verb = MGCP_VERB_CRCX,
 		.presence = (MGCP_MSG_PRESENCE_ENDPOINT | MGCP_MSG_PRESENCE_CALL_ID | MGCP_MSG_PRESENCE_CONN_MODE),
 		.call_id = mgcp_ctx->conn_peer_local.call_id,
-		.conn_mode = MGCP_CONN_LOOPBACK,
+		.conn_mode = MGCP_CONN_RECV_ONLY,
 	};
 	osmo_strlcpy(mgcp_msg.endpoint, mgcp_ctx->conn_peer_local.endpoint, MGCP_ENDPOINT_MAXLEN);