Dont attempt to get size within archive process, will return empty; ref pterodactyl/panel#2420

The stat call is operating against an unflushed file if called in the archive function, so you'll just get the emtpy archive size, rather than the final size.

Plus, we only used the file stat in one place, so slight efficiency win?

server/backup/backup_s3.go

@@ -33,7 +33,7 @@ func (s *S3Backup) Generate(included *IncludedFiles, prefix string) (*ArchiveDet
 		Files:      included,
 	}
 
-	if _, err := a.Create(s.Path(), context.Background()); err != nil {
+	if err := a.Create(s.Path(), context.Background()); err != nil {
 		return nil, errors.WithStack(err)
 	}