[ImgBot] Optimize images

*Total -- 7,115.84kb -> 1,230.05kb (82.71%)

/preview/reports.gif -- 2,093.17kb -> 99.71kb (95.24%)
/preview/tracking.gif -- 5,022.67kb -> 1,130.35kb (77.5%)

Signed-off-by: ImgBotApp <ImgBotHelp@gmail.com>

Author: ImgBotApp