better error on jmp-fwdcall's new "anonymous" JIDs
Denver Gingerich
created
When the user tries to send a message to an "anonymous" JID (the type
of JID that jmp-fwdcalls will create when it gets a blocked caller ID,
as of https://gitlab.com/ossguy/jmp-fwdcalls/commit/e2032c8 anyway)
provide a more appropriate error message, as the JID does exist, it's
just that the user who left the voicemail isn't available at that JID.