Fix severity level sorting without changing test

ee/app/services/security/dependency_list_service.rb

@@ -72,8 +72,8 @@ module Security
     # will have highest severity
     def sort_by_severity(collection)
       collection.sort do |dep_i, dep_j|
-        level_i = dep_i.dig(:vulnerabilities, 0, :severity) || :unknown
-        level_j = dep_j.dig(:vulnerabilities, 0, :severity) || :unknown
+        level_i = dep_i.dig(:vulnerabilities, 0, :severity) || :info
+        level_j = dep_j.dig(:vulnerabilities, 0, :severity) || :info
 
         ::Vulnerabilities::Occurrence::SEVERITY_LEVELS[level_j] <=> ::Vulnerabilities::Occurrence::SEVERITY_LEVELS[level_i]
       end

ee/spec/controllers/projects/dependencies_controller_spec.rb

@@ -117,7 +117,7 @@ describe Projects::DependenciesController do
 
                 it 'returns sorted list' do
                   expect(json_response['dependencies'].first['name']).to eq('nokogiri')
-                  expect(json_response['dependencies'].second['name']).to eq('mini_portile2')
+                  expect(json_response['dependencies'].second['name']).to eq('debug')
                 end
               end
             end