mod_roster_command: Fix subscription when the "user JID" is a bare domain. Do not attempt to update the roster when the user is bare domain (e.g. a component), since they don't have rosters and the attempt results in an error: $ prosodyctl mod_roster_command subscribe proxy.example.com contact@example.com xxxxxxxxxxFailed to execute command: Error: /usr/lib/prosody/core/rostermanager.lua:104: attempt to concatenate local 'username' (a nil value) stack traceback: /usr/lib/prosody/core/rostermanager.lua:104: in function 'load_roster' /usr/lib/prosody/core/rostermanager.lua:305: in function 'set_contact_pending_out' mod_roster_command.lua:44: in function 'subscribe'

---
labels:
- 'Stage-Beta'
- 'Type-Storage'
summary: 'Lightning Memory-Mapped Database storage'
...

Introduction
============

This is a storage module using OpenLDAP Lightning Memory-Mapped Database
as backend.

Dependencies
============

[lightningdbm](https://github.com/shmul/lightningdbm) is required to
access LMDB databases.

Details
=======

Refer to [Prosodys data storage
documentation](https://prosody.im/doc/storage).

Compatibility
=============

  -------- -------------
  \>=0.9   Should work
  -------- -------------