prevent instant death

In my games player frequently died by malus bubbles added to positions already at the limit. Often with lots of free space next to a single low tail.
After this had annoyed me often enough I tried to adjust the malus generation such that malus bubbles are not placed below the line. (Of course you can still be unlucky and get a malus bubble just above the line right before the whole stack advances...)

I played several test games and it seems to work properly. I did not notice any new problem. 
It would be nice to get this into the next release, if you think this is an improvement to the game-play too.