[ImgBot] Optimize images

*Total -- 2,128.15kb -> 2,106.07kb (1.04%)

/Assets/Materials/prototype/Textures/prototype_512x512_normal.png -- 2.86kb -> 1.20kb (57.93%)
/Assets/Materials/prototype/Textures/prototype_512x512_green3.png -- 4.59kb -> 2.51kb (45.27%)
/Assets/Materials/prototype/Textures/prototype_512x512_magenta.png -- 4.53kb -> 2.51kb (44.63%)
/Assets/Materials/prototype/Textures/prototype_512x512_pink.png -- 4.52kb -> 2.51kb (44.42%)
/Assets/Materials/prototype/Textures/prototype_512x512_olive.png -- 4.40kb -> 2.51kb (42.99%)
/Assets/Materials/prototype/Textures/prototype_512x512_white.png -- 3.39kb -> 2.45kb (27.77%)
/Assets/Materials/prototype/Textures/prototype_512x512_grey4.png -- 3.40kb -> 2.46kb (27.61%)
/Assets/Materials/prototype/Textures/prototype_512x512_brown.png -- 3.40kb -> 2.49kb (26.72%)
/Assets/Materials/prototype/Textures/prototype_512x512_cyan.png -- 3.40kb -> 2.49kb (26.72%)
/Assets/Materials/prototype/Textures/prototype_512x512_purple.png -- 3.40kb -> 2.49kb (26.72%)
/Assets/Materials/prototype/Textures/prototype_512x512_red.png -- 3.40kb -> 2.49kb (26.72%)
/Assets/Materials/prototype/Textures/prototype_512x512_blue3.png -- 3.40kb -> 2.49kb (26.72%)
/Assets/Materials/prototype/Textures/prototype_512x512_green2.png -- 3.40kb -> 2.49kb (26.72%)
/Assets/Materials/Fantasy Skybox FREE/Materials/Classic/FS000_Night_02_Moonless.png -- 332.01kb -> 330.25kb (0.53%)
/Assets/Materials/Fantasy Skybox FREE/Materials/Classic/FS000_Day_05_Sunless.png -- 507.97kb -> 506.50kb (0.29%)
/Assets/Materials/Fantasy Skybox FREE/Materials/Classic/FS000_Day_05.png -- 522.15kb -> 520.68kb (0.28%)
/Assets/Materials/Fantasy Skybox FREE/Materials/Classic/FS000_Day_04.png -- 717.95kb -> 717.55kb (0.06%)

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