Fix rubocop offenses in upload rewriter specs

spec/lib/gitlab/gfm/uploads_rewriter_spec.rb

@@ -13,7 +13,7 @@ describe Gitlab::Gfm::UploadsRewriter do
 
     let(:zip_uploader) do
       build(:file_uploader, project: old_project,
-            fixture: 'ci_build_artifacts.zip')
+                            fixture: 'ci_build_artifacts.zip')
     end
 
     let(:text) do