remove code that never got executed

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7050 8aca7d54-2c30-db11-9de9-000461428c89
ADD: server_motd_filename for file with a greeting message in online games

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@7051 8aca7d54-2c30-db11-9de9-000461428c89