Fix transparent pixels
Fix transparent pixels

( reported by Agamemnus - http://forum.simutrans.com/index.php?topic=9218.0 )

git-svn-id: ad2a872dfb5accdcee22c80d0a136769e8f61d01@783 e96eaf88-093e-0410-925f-862d53288611

simutrans/pak128,simutrans/pak128,simutrans/pak128,simutrans/pak128,simutrans/pak128