My b2evolution Version: Not Entered

I am trying to authenticate if my currant version is 4.0.5

If I accidentally replaced "conf/_application.php" on my 4.0.5 with a version of 4.0.3:

Is there possibly a line of code embedded somewhere within version 4.0.5 which I can look at which will not be present in any version earlier than 4.0.5?