Fix number of endpoints of default trunk

If a config file doesn't have a 'number endpoints' config line,
we would use -1 as unsigned integer and end up with
 number endpoints 4294967295
if the config file is re-written

Change-Id: I05a3814117b1d6e0cdc30740da31709ce333df4b
Closes: OS#4034
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index c72596a..12fea1d 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -1620,7 +1620,7 @@
 
 	cfg->get_net_downlink_format_cb = &mgcp_get_net_downlink_format_default;
 
-	/* default trunk handling */
+	/* default trunk handling; TODO: avoid duplication with mgcp_trunk_alloc() below */
 	cfg->trunk.cfg = cfg;
 	cfg->trunk.trunk_nr = 0;
 	cfg->trunk.trunk_type = MGCP_TRUNK_VIRTUAL;
@@ -1628,6 +1628,7 @@
 	cfg->trunk.audio_payload = 126;
 	cfg->trunk.audio_send_ptime = 1;
 	cfg->trunk.audio_send_name = 1;
+	cfg->trunk.vty_number_endpoints = 33;
 	cfg->trunk.omit_rtcp = 0;
 	mgcp_trunk_set_keepalive(&cfg->trunk, MGCP_KEEPALIVE_ONCE);
 	if (alloc_mgcp_rate_counters(&cfg->trunk, cfg) < 0) {