Chisel Corner Fix (#4756)

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## About The Pull Request

Port of: PentestSS13/Pentest#284

Chisel corners got reset back to the original appearance when a shuttle
moved. This PR fixes that, though it has nothing to do with the chisel
itself. I have tested it over multiple trips and it appears to work
fine.

I have not tested it with ship rotation/docking, but it will likely work
just fine. copyTurf() is problematic as I note in [a different
PR](PentestSS13/Pentest#288).

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## Why It's Good For The Game

Took way too long to pin down. Makes ships pretty.

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## Changelog

:cl:
fix: Chisel corners will now be preserved when the ship moves.
/:cl:

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Author: FslashN

code/game/turfs/change_turf.dm

@@ -34,6 +34,8 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 		T.update_atom_colour()
 	if(T.dir != dir)
 		T.setDir(dir)
+	if(T.smoothing_flags != smoothing_flags)
+		T.smoothing_flags = smoothing_flags
 	return T
 
 /turf/open/copyTurf(turf/T, copy_air = FALSE)