mod_report_affiliations: Fix traceback a non-user is sending a presence For now we won’t touch their presence instead of emiting this traceback: error Traceback[s2s]: /usr/lib/prosody/core/rostermanager.lua:275: attempt to concatenate a nil value (local 'username') stack traceback: /usr/lib/prosody/core/rostermanager.lua:275: in function 'prosody.core.rostermanager.is_user_subscribed' ...ules/mod_report_affiliations/mod_report_affiliations.lua:116: in field '?' /usr/lib/prosody/util/events.lua:81: in function </usr/lib/prosody/util/events.lua:77> (...tail calls...) /usr/lib/prosody/core/stanza_router.lua:184: in upvalue 'core_post_stanza' /usr/lib/prosody/modules/mod_presence.lua:244: in function </usr/lib/prosody/modules/mod_presence.lua:231> (...tail calls...) /usr/lib/prosody/util/events.lua:81: in function </usr/lib/prosody/util/events.lua:77> (...tail calls...) /usr/lib/prosody/core/stanza_router.lua:188: in upvalue 'core_post_stanza' /usr/lib/prosody/core/stanza_router.lua:128: in upvalue 'core_process_stanza' /usr/lib/prosody/modules/mod_s2s.lua:818: in upvalue 'func' /usr/lib/prosody/util/async.lua:149: in function </usr/lib/prosody/util/async.lua:147>

---
summary: Workaround for Dialback with some servers that violate RFC 6120
...

This module provides a workaround for servers that do not set the `to`
attribute on stream headers, which is required per [RFC6120]:

> ## 4.7.2. to
> 
> For initial stream headers in both client-to-server and
> server-to-server communication, the initiating entity MUST include the
> 'to' attribute and MUST set its value to a domainpart that the
> initiating entity knows or expects the receiving entity to service.

As a side effect of [this issue](https://prosody.im/issues/issue/285),
Prosody 0.10 will be unable to do [Dialback][xep220] with servers that
don't follow this.

# Known servers affected

* Openfire 3.10.2 (and probably earlier versions)