hide NoUUID remotes from repolist

A ssh remote will breifly have NoUUID when it's just being set up and
git-annex-shell has not yet been queried for the UUID. So it doesn't make
sense to display any kind of error message in this case. The UI doesn't
work when there's NoUUID, and it can even crash the ajax long polling code.
So hiding NoUUID repositories is the right thing to do.

I've tested and the automatic refresh of the repolist causes the remote
to show up as soon as a UUID is recorded, when doing local pairing, and
when adding a ssh remote.

Assistant/WebApp/RepoList.hs

@@ -177,7 +177,8 @@ repoList reposelector
 	  where
 		val iscloud r = Just (iscloud, (u, DisabledRepoActions $ r u))
 	list l = liftAnnex $ do
-		let l' = nubBy (\x y -> fst x == fst y) l
+		let l' = filter (\(u, _) -> u /= NoUUID) $
+			nubBy (\x y -> fst x == fst y) l
 		l'' <- zip
 			<$> Remote.prettyListUUIDs (map fst l')
 			<*> pure l'