If an incoming OMEMO message failed to decrypt (due to missing session
keys or untrusted identities), Profanity would fall back to displaying
the raw XMPP body. This usually contained a generic string like "This
message is encrypted with OMEMO,".
We wrote the detailed reason in the debug logs but the user only saw the
fallback message and probably wondered *why* the message wasn't
displayed properly.
I'm unsure if we should display the fallback message as well though.