Respond to proper format for build badge request

app/controllers/projects/builds_controller.rb

@@ -62,9 +62,15 @@ class Projects::BuildsController < Projects::ApplicationController
 
   def badge
     project = Project.find_with_namespace("#{params[:namespace_id]}/#{params[:project_id]}")
+
+    respond_to do |format|
+      format.html { render_404 }
+      format.svg do
         image = Ci::ImageForBuildService.new.execute(project, ref: params[:ref])
         send_file(image.path, filename: image.name, disposition: 'inline', type: 'image/svg+xml')
       end
+    end
+  end
 
   private