no redirect to work_packages/ as this has issues

less problems with:
https://www.openproject.org/work_packages/11099
See:
https://github.com/opf/openproject/blob/dev/spec/requests/old_issue_2_wp_spec.rb
and
https://github.com/opf/openproject/blob/dev/spec/requests/short_uri_wp_spec.rb
;-)