FIX: build pillars up to correct height (kierongreen)

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6549 8aca7d54-2c30-db11-9de9-000461428c89
FIX crash when renovating building near map border

git-svn-id: svn://tron.homeunix.org/simutrans/simutrans/trunk@6550 8aca7d54-2c30-db11-9de9-000461428c89