fix Various Artists dont have artist cover

main.go

@@ -1405,11 +1405,13 @@ func rip(albumId string, token string, storefront string, userToken string) erro
 	fmt.Println(albumFolder)
 	//get artist cover
 	if config.SaveArtistCover && !(strings.Contains(albumId, "pl.")) {
+		if len(meta.Data[0].Relationships.Artists.Data) > 0 {
 			err = writeCover(singerFolder, "folder", meta.Data[0].Relationships.Artists.Data[0].Attributes.Artwork.Url)
 			if err != nil {
 				fmt.Println("Failed to write artist cover.")
 			}
 		}
+	}
 	//get album cover
 	err = writeCover(sanAlbumFolder, "cover", meta.Data[0].Attributes.Artwork.URL)
 	if err != nil {

main_atmos.go

@@ -1321,11 +1321,13 @@ func rip(albumId string, token string, storefront string, userToken string) erro
 	fmt.Println(albumFolder)
 	//get artist cover
 	if config.SaveArtistCover && !(strings.Contains(albumId, "pl.")) {
+		if len(meta.Data[0].Relationships.Artists.Data) > 0 {
 			err = writeCover(singerFolder, "folder", meta.Data[0].Relationships.Artists.Data[0].Attributes.Artwork.Url)
 			if err != nil {
 				fmt.Println("Failed to write artist cover.")
 			}
 		}
+	}
 	//get album cover
 	err = writeCover(sanAlbumFolder, "cover", meta.Data[0].Attributes.Artwork.URL)
 	if err != nil {

main_select.go

@@ -1281,11 +1281,13 @@ func rip(albumId string, token string, storefront string, userToken string) erro
 	fmt.Println(albumFolder)
 	//get artist cover
 	if config.SaveArtistCover && !(strings.Contains(albumId, "pl.")) {
+		if len(meta.Data[0].Relationships.Artists.Data) > 0 {
 			err = writeCover(singerFolder, "folder", meta.Data[0].Relationships.Artists.Data[0].Attributes.Artwork.Url)
 			if err != nil {
 				fmt.Println("Failed to write artist cover.")
 			}
 		}
+	}
 	//get album cover
 	err = writeCover(sanAlbumFolder, "cover", meta.Data[0].Attributes.Artwork.URL)
 	if err != nil {