Render order changed in animation
piece1 -> image1
piece3 -> image2
piece2 -> image2
When render order is changed, a piece with no image (currentSprite) will not cause the child in phaser's hierarchy to be updated. This results in duplicate children.
This fixes the following scenario (animated piece -> phaser display object child):
Initial animation setup piece1 -> image1 piece2 -> image2 piece3 -> no image
Render order changed in animation piece1 -> image1 piece3 -> image2 piece2 -> image2
When render order is changed, a piece with no image (currentSprite) will not cause the child in phaser's hierarchy to be updated. This results in duplicate children.