FIX: actually set percent

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6459 8aca7d54-2c30-db11-9de9-000461428c89
FIX (ArthurDenture) stop midi playing on mac upon quit

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6460 8aca7d54-2c30-db11-9de9-000461428c89