[mgcp] Only write audio_name/payload when it is actually set.
diff --git a/openbsc/src/mgcp/mgcp_vty.c b/openbsc/src/mgcp/mgcp_vty.c
index 743f3fd..6bfb287 100644
--- a/openbsc/src/mgcp/mgcp_vty.c
+++ b/openbsc/src/mgcp/mgcp_vty.c
@@ -55,8 +55,10 @@
vty_out(vty, " bind port %u%s", g_cfg->source_port, VTY_NEWLINE);
vty_out(vty, " bind early %u%s", !!g_cfg->early_bind, VTY_NEWLINE);
vty_out(vty, " rtp base %u%s", g_cfg->rtp_base_port, VTY_NEWLINE);
- vty_out(vty, " sdp audio payload number %u%s", g_cfg->audio_payload, VTY_NEWLINE);
- vty_out(vty, " sdp audio payload name %s%s", g_cfg->audio_name, VTY_NEWLINE);
+ if (g_cfg->audio_payload != -1)
+ vty_out(vty, " sdp audio payload number %d%s", g_cfg->audio_payload, VTY_NEWLINE);
+ if (g_cfg->audio_name)
+ vty_out(vty, " sdp audio payload name %s%s", g_cfg->audio_name, VTY_NEWLINE);
vty_out(vty, " loop %u%s", !!g_cfg->audio_loop, VTY_NEWLINE);
vty_out(vty, " endpoints %u%s", g_cfg->number_endpoints, VTY_NEWLINE);
if (g_cfg->forward_ip)