Removes 'no job log' from trace action

'No job log' message is no longer necessary since we returned an image
when a build does not have a trace. See
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18278 for more
details

Closes #45625

app/controllers/projects/jobs_controller.rb

@@ -78,8 +78,6 @@ class Projects::JobsController < Projects::ApplicationController
             result.merge!(trace.to_h)
           end
 
-          result[:html] = result[:html].presence || 'No job log'
-
           render json: result
         end
       end

changelogs/unreleased/45625-job-log-shows-no-job-log.yml

+---
+title: Removes 'No Job log' message from build trace
+merge_request: 18523
+author:
+type: fixed

spec/controllers/projects/jobs_controller_spec.rb

@@ -190,10 +190,7 @@ describe Projects::JobsController do
         expect(response).to have_gitlab_http_status(:ok)
         expect(json_response['id']).to eq job.id
         expect(json_response['status']).to eq job.status
-      end
-
-      it 'returns no job log message' do
-        expect(json_response['html']).to eq('No job log')
+        expect(json_response['html']).to be_nil
       end
     end