[0.17.48] [Minor] Construction bot working animation's shadow is peculiar

[Deadlock989]

When construction bots are repairing a damaged machine, they flit around making sparks, humming their little robot tunes.

But their shadow does a strange waggle-dance, reminiscent of a worker bee dancing out a message, or perhaps a tiny, tiny Miley Cyrus. It's strangely troubling. It looks like it is flicking back and forth between different "directions".

I'm not sure but I think that the shadow_working property of construction bots changed at some point in 0.17 because the definitions I have don't work at all any more. It's something to do with how the shadow sprite is horizontal because it's also used for shadow_idle and shadow_in_motion, but for shadow_working, it has be finessed to be vertical to match up with the vertical 2 frame working sprite sheet for the bot's main animation. It has finessed this using stripes and the util.multiplystripes function for a while, but the results it's producing are off and I can't work out how to fix it (so I can't fix my own bots either).

Steps to reproduce:

1. Damage one of your own force's entities while in range of a roboport equipped with construction bots and repair packs.
2. Bots will go to repair the structure.
3. Watch their shadows.

Edited to add gif of the waggling:

[posila]

Thanks for the report.
Fixed for 0.17.49