refactor rubocop suggestion

app/controllers/projects/compare_controller.rb

@@ -65,4 +65,4 @@ class Projects::CompareController < Projects::ApplicationController
     @merge_request ||= MergeRequestsFinder.new(current_user, project_id: @project.id).execute.opened.
       find_by(source_project: @project, source_branch: @head_ref, target_branch: @start_ref)
   end
-end
\ No newline at end of file
+end