fix(api): ensure getFavoriteGifs doesn't error when response is empty

services/gif/gif.go

@@ -149,11 +149,14 @@ func (api *API) GetFavoriteGifs() (favoriteGifs []Gif, err error) {
 	if err != nil {
 		return nil, err
 	}
+	favoriteGifs = make([]Gif, 0)
 	savedFavGifs := []Gif{}
+	if len(gifs) > 0 {
 		err = json.Unmarshal(gifs, &savedFavGifs)
 		if err != nil {
 			return nil, err
 		}
 		favoriteGifs = savedFavGifs
+	}
 	return favoriteGifs, nil
 }