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>

This module provides two [metrics][doc:statistics]:

`lua_heap_bytes`
:   Bytes of memory as reported by `collectgarbage("count")`{.lua}

`lua_info`
:   Provides the current Lua version as a label

``` openmetrics
# HELP lua_info Lua runtime version
# UNIT lua_info
# TYPE lua_info gauge
lua_info{version="Lua 5.4"} 1
# HELP lua_heap_bytes Memory used by objects under control of the Lua
garbage collector
# UNIT lua_heap_bytes bytes
# TYPE lua_heap_bytes gauge
lua_heap_bytes 8613218
```