fix(Songs): requestSet could return null songs

backend/logic/actions/songs.js

@@ -1191,7 +1191,7 @@ export default {
 									else failed += 1;
 									if (res.message === "This song is already in the database.") alreadyInDatabase += 1;
 									if (res.song) songs[index] = res.song;
-									else songs[index] = null;
+									else failed += 1;
 								})
 								.catch(() => {
 									failed += 1;