[ImgBot] Optimize images

*Total -- 517.81kb -> 419.15kb (19.05%)

/practice/Assets.xcassets/red amp.imageset/red amp.png -- 119.42kb -> 86.95kb (27.19%)
/practice/Assets.xcassets/chain.imageset/chain.png -- 186.55kb -> 148.33kb (20.49%)
/practice/Assets.xcassets/blue speaker.imageset/blue speaker.png -- 106.27kb -> 91.76kb (13.65%)
/practice/Assets.xcassets/red speaker.imageset/red speaker.png -- 105.57kb -> 92.11kb (12.75%)

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Author: ImgBotApp