ggsn: ctrl iface: listen on IP configured by VTY

Previosuly, the CTRL iface of osmo-ggsn was always bound to 127.0.0.1

Fixes: OS#3287
Change-Id: I9b2c1b310c7dc94ef09642f7f256ae259b41619d
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index 14bf04f..6d879c0 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -1111,7 +1111,8 @@
 	if (rc < 0)
 		exit(1);
 
-	g_ctrlh = ctrl_interface_setup(NULL, OSMO_CTRL_PORT_GGSN, NULL);
+	g_ctrlh = ctrl_interface_setup_dynip(NULL, ctrl_vty_get_bind_addr(),
+					     OSMO_CTRL_PORT_GGSN, NULL);
 	if (!g_ctrlh) {
 		LOGP(DGGSN, LOGL_ERROR, "Failed to create CTRL interface.\n");
 		exit(1);