fix init default description reversion

init: Fix a reversion in the last release that prevented automatically
generating and setting a description for the repository.

Seemed best to factor out uuidDescMapRaw that does not
have the default mempty descrition behavior.

I don't much like that behavior, but I know things depend on it.
One thing in particular is `git annex info` which lists the uuids and
descriptions; if the current repo has been initialized in some way that
means it does not have a description, it would not show up w/o that.

(Not only repos created due to this bug might lack that. For example a repo
that was marked dead and had --drop-dead delete its git-annex branch info,
and then came back from the dead would similarly not be in the uuid.log.
Also there have been other versions of git-annex that didn't set a default
description; for years there was no default description.)

Annex/Init.hs

@@ -92,7 +92,7 @@ initialize mdescription mversion = checkCanInitialize $ do
 	u <- getUUID
 	{- Avoid overwriting existing description with a default
 	 - description. -}
-	whenM (pure (isJust mdescription) <||> not . M.member u <$> uuidDescMap) $
+	whenM (pure (isJust mdescription) <||> not . M.member u <$> uuidDescMapRaw) $
 		describeUUID u =<< genDescription mdescription
 
 -- Everything except for uuid setup, shared clone setup, and initial