Fix calculation of Active Record :db_runtime metric

Author: fatkodima

activerecord/lib/active_record/runtime_registry.rb

@@ -25,5 +25,5 @@ def reset
 end
 
 ActiveSupport::Notifications.monotonic_subscribe("sql.active_record") do |name, start, finish, id, payload|
-  ActiveRecord::RuntimeRegistry.sql_runtime += (finish - start) * 1_000.0
+  ActiveRecord::RuntimeRegistry.sql_runtime += (finish - start)
 end