mod_bookmarks2: Use max_items='max' on trunk, with fallback check_node_config() throws an error attempting to compare the pep_max_items number with the 'max' string, which allows detecting and support using 'max' where available. Unsure what happens when you upgrade, that seems a problem for a future commit! :)

This module helps make BOSH and WebSocket connection endpoints
discoverable via the HTTP method described in
[XEP-0156](https://xmpp.org/extensions/xep-0156.html#http).