bugfix: Make sure that farbled APIs produce the same results even when the extension configuration changes
    
    Previously all wrappers shared the same random generator but that means
    that the generated random value depended on the order of the call to the
    random function.
    
    Hence, if a user enabled or disabled an affected wrapper, other wrappers
    might have get a different random number, change its output and possibly
    change a fingerprint that should have been stable for the session.