[2.1.9] Obsolete assembling-machine-2 and chemical-plant textures

[Ingo-Igel]

Under “Factorio\data\base\graphics\entity\assembling-machine-2”
there is an obsolete texture named “assembling-machine-2.png,”
and under “Factorio\data\base\graphics\entity\chemical-plant”
there is an obsolete texture named “chemical-plant.png.”

Neither of the two textures mentioned is used anywhere; they appear to be leftover from the development phase of 2.1 and to have been overlooked.