[ImgBot] Optimize images

*Total -- 220.75kb -> 179.75kb (18.57%)

/static/en/img/config-repositories.png -- 72.91kb -> 56.17kb (22.97%)
/static/en/img/update-extension.png -- 41.38kb -> 34.19kb (17.37%)
/static/en/img/uninstall-extension.png -- 55.98kb -> 46.74kb (16.51%)
/static/en/img/install-extension.png -- 50.48kb -> 42.65kb (15.51%)

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

Author: ImgBotApp