fsck: Avoid complaining about required content of dead repositories

requiredContentMap does not exclude dead repos. Usually this is not a
problem because it is used when we are operating on a repository, and in
that case, the repository is not dead (or if it is, the required content
configurations should still be used). But in the case of fsck, this made a
old required content config for a dead repository be warned about in a
situation where it is not a problem.

Command/Fsck.hs

@@ -375,11 +375,13 @@ verifyRequiredContent key ai@(ActionItemAssociatedFile afile _) = case afile of
 	-- Can't be checked if there's no associated file.
 	AssociatedFile Nothing -> return True
 	AssociatedFile (Just _) -> do
-		requiredlocs <- S.fromList . M.keys <$> requiredContentMap
-		if S.null requiredlocs
+		requiredlocs <- filterM notdead =<< (M.keys <$> requiredContentMap)
+		if null requiredlocs
 			then return True
-			else go requiredlocs
+			else go (S.fromList requiredlocs)
   where
+	notdead u = (/=) DeadTrusted <$> lookupTrust u
+
 	go requiredlocs = do
 		presentlocs <- S.fromList <$> loggedLocations key
 		missinglocs <- filterM