support annex-config-uuid when generating remote

This is used by a special remote with sameas-uuid=
The remote's uuid is the sameas-uuid, but it needs to get
its RemoteConfig from the annex-config-uuid.

Remote/List.hs

@@ -105,7 +105,8 @@ remoteGen :: M.Map UUID RemoteConfig -> RemoteType -> Git.Repo -> Annex (Maybe R
 remoteGen m t g = do
 	u <- getRepoUUID g
 	gc <- Annex.getRemoteGitConfig g
-	let c = fromMaybe M.empty $ M.lookup u m
+	let cu = fromMaybe u $ remoteAnnexConfigUUID gc
+	let c = fromMaybe M.empty $ M.lookup cu m
 	generate t g u c gc >>= \case
 		Nothing -> return Nothing
 		Just r -> Just <$> adjustExportImport (adjustReadOnly (addHooks r))

doc/todo/support_multiple_special_remotes_with_same_uuid.mdwn

@@ -34,8 +34,6 @@ the remote.log. Eg, "B sameas=A foo=bar ..."
 
 Implementation notes:
 
-Next, need to make generating a Remote look at annex-config-uuid.
-
 Need to get enableremote working for sameas.
 
 Deal with the per-remote state issue.