mod_report_forward: Fix traceback on error message passed to datetime function If archive:get() returns an error, e.g. because it can't find a message with the given ID, it may return e.g. nil, "item-not-found" or similar where the error condition ends up in reported_message_time, which gets passed to util.datetime, which thus ends up doing math to a string or error object.

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summary: Set process name to prosody
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This module sets the process name to `prosody` so it shows up as such
instead of `lua` in process management tools.

To use this module, you'll need the proctitle Lua library:
<https://github.com/hoelzro/lua-proctitle>