fix editing unknown uuid

Before, assumed Nothing when getting remote meant it was the local repo,
and showed the edit form for that.

Assistant/WebApp/Configurators/Edit.hs

@@ -37,6 +37,7 @@ import Git.Remote
 import Remote.Helper.Encryptable (extractCipher)
 import Types.Crypto
 import Utility.Gpg
+import Annex.UUID
 
 import qualified Data.Text as T
 import qualified Data.Map as M
@@ -178,6 +179,9 @@ postEditNewCloudRepositoryR uuid = xmppNeeded >> editForm True uuid
 editForm :: Bool -> UUID -> Handler Html
 editForm new uuid = page "Edit repository" (Just Configuration) $ do
 	mremote <- liftAnnex $ Remote.remoteFromUUID uuid
+	when (mremote == Nothing) $
+		whenM ((/=) uuid <$> liftAnnex getUUID) $
+			error "unknown remote"
 	curr <- liftAnnex $ getRepoConfig uuid mremote
 	liftAnnex $ checkAssociatedDirectory curr mremote
 	((result, form), enctype) <- liftH $