FEATURE: remove any .tar leftovers when backing up

lib/backup_restore/backuper.rb

@@ -283,6 +283,7 @@ module BackupRestore
 
     def clean_up
       log "Cleaning stuff up..."
+      remove_tar_leftovers
       remove_tmp_directory
       unpause_sidekiq
       disable_readonly_mode if Discourse.readonly_mode?
@@ -290,6 +291,11 @@ module BackupRestore
       log "Finished!"
     end
 
+    def remove_tar_leftovers
+      log "Removing '.tar' leftovers..."
+      `rm -f #{@archive_directory}/*.tar`
+    end
+
     def remove_tmp_directory
       log "Removing tmp '#{@tmp_directory}' directory..."
       FileUtils.rm_rf(@tmp_directory) if Dir[@tmp_directory].present?