Refactor method in Session::MagicColumns::InstanceMethods

refactored the complex method `update_info` as recommended by Code Climate: https://codeclimate.com/github/binarylogic/authlogic/Authlogic::Session::MagicColumns::InstanceMethods

I moved two `if`s to separate lines in `update_info`. This makes it clear that every section of the method checks `record.respond_to?` before setting a column value. Before, it looked like the first two lines did something substantially different from the rest of the method. This also more clearly separates the method response checking from the calculation of the correct value.