Rails5: fix artifacts controller download spec
What does this MR do?
'' if file_type is included as nil in the spec request params. This is not what happens on a real request if no
file_type is send from the browser, the parameter will simply not exist. I changed the spec to send no
file_type param, instead of a param that is
spec/controllers/projects/artifacts_controller_spec.rb:28, See https://gitlab.com/gitlab-org/gitlab-ce/-/jobs/104515016