Let libosmocore handle VTY parent node tracking

* is_config_node is deprecated, so don't set it
* go_parent_cb is only used if we want to do special stuff upon exiting
  a node, in osmo-sgsn and gtphub only osmo_ss7_vty_go_parent() needs to
  be called

Change-Id: I2008dd9026922d29ee703c59e70d3fecced0ee18
diff --git a/src/gb_proxy_main.c b/src/gb_proxy_main.c
index f8c5ade..63e5f49 100644
--- a/src/gb_proxy_main.c
+++ b/src/gb_proxy_main.c
@@ -183,39 +183,9 @@
 	}
 }
 
-int gbproxy_vty_is_config_node(struct vty *vty, int node)
-{
-        switch (node) {
-        /* add items that are not config */
-        case CONFIG_NODE:
-                return 0;
-
-        default:
-                return 1;
-        }
-}
-
-int gbproxy_vty_go_parent(struct vty *vty)
-{
-        switch (vty->node) {
-        case GBPROXY_NODE:
-        default:
-                if (gbproxy_vty_is_config_node(vty, vty->node))
-                        vty->node = CONFIG_NODE;
-                else
-                        vty->node = ENABLE_NODE;
-
-                vty->index = NULL;
-        }
-
-        return vty->node;
-}
-
 static struct vty_app_info vty_info = {
 	.name 		= "OsmoGbProxy",
 	.version	= PACKAGE_VERSION,
-	.go_parent_cb	= gbproxy_vty_go_parent,
-	.is_config_node	= gbproxy_vty_is_config_node,
 };
 
 /* default categories */