appview: state: Ensure failure to retrieve stars returns early.

appview/state/star.go

···
 		starCount, err := db.GetStarCount(s.db, subjectUri)
 		if err != nil {
 			log.Println("failed to get star count for ", subjectUri)
+			return
 		}
 
 		s.pages.RepoActionsFragment(w, pages.RepoActionsFragmentParams{