Remove discriminator from new images to existing submissions

src/commands/challenge.rs

@@ -125,10 +125,9 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
                 }
                 requires_rebuild = true;
                 let file_name = format!(
-                    "{}-{}-{}-{}{}.{}",
+                    "{}-{}-{}{}.{}",
                     i + 1,
                     slugify(&author.name),
-                    author.discriminator,
                     timestamp,
                     if i == 0 {
                         "".to_owned()