BonusBlocks are placed in the wrong position when transformed to objects

[Narre]

SuperTux version: current git version (commit f6ea1f8)
System information: Ubuntu 19.10 64bit

When a level is started, the game transforms all bonusblocks placed in tilemaps to objects, but:

Expected behaviour: bonusblocks are placed in the same position as the tile-bonusblock

Actual behaviour: bonusblocks are placed in the wrong position

The position is not entirely incorrect - but it is relative to the entire sector while it should be relative to the position of the tilemap the tile-bonusblocks were in.

Steps to reproduce actual behaviour: Create a new level, in that level, create a tilemap and put it anywhere but x=0, y=0. Put bonusblocks(or coins, or anything that transforms into an object) in the top-left corner. Now, if you play the level, the bonusblocks won't be in the top-left of the tilemap, but in the top-left of the entire sector. (top-left is just for illustration, it works the same anywhere)

I'm not sure when this bug first appeared but I know for sure this worked fine in 0.5.1