Merge branch 'fix/import-export-note-attachments' into 'master'

fix TODO comment

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/20376

After some testing, I've found out this wasn't needed and attachments seemed to work fine for import/export between instances (omnibus & source).

See merge request !5617

lib/gitlab/import_export/relation_factory.rb

@@ -44,7 +44,7 @@ module Gitlab
         if @relation_name == :notes
           set_note_author
 
-          # TODO: note attatchments not supported yet
+          # attachment is deprecated and note uploads are handled by Markdown uploader
           @relation_hash['attachment'] = nil
         end