[ImgBot] Optimize images

*Total -- 54.12kb -> 28.25kb (47.79%)

/img/fusionStats.png -- 18.70kb -> 7.11kb (61.99%)
/img/fusionStats_gr.png -- 35.42kb -> 21.15kb (40.3%)

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

Author: ImgBotApp