Fix send_file_upload_spec.rb with right MIME type

This fixes a regression in mime-types-data:
mime-types/mime-types-data#20

spec/controllers/concerns/send_file_upload_spec.rb

@@ -115,7 +115,7 @@ def dynamic_segment
 
         it 'sends a file with a custom type' do
           headers = double
-          expected_headers = /response-content-disposition=attachment%3B%20filename%3D%22test.js%22%3B%20filename%2A%3DUTF-8%27%27test.js&response-content-type=application%2Fecmascript/
+          expected_headers = /response-content-disposition=attachment%3B%20filename%3D%22test.js%22%3B%20filename%2A%3DUTF-8%27%27test.js&response-content-type=application%2Fjavascript/
           expect(Gitlab::Workhorse).to receive(:send_url).with(expected_headers).and_call_original
           expect(headers).to receive(:store).with(Gitlab::Workhorse::SEND_DATA_HEADER, /^send-url:/)