screen_saver_timeout resetting

[grgohr]

after some time the screensaver does not trigger anymore
it seems that the screen_saver_timeout variable is reset and not taking into account the value set in AttractMode setup (on my side 25 seconds).
in the code I see m_ssaver_time( 600 ) which looks close to what I observe.

I could not find a way to overwrite the global variable screen_saver_timeout in screensaver.nut (or any other actual, the "::variable <- value;" code for Squirrel leaves me with unknown variable)