[ImgBot] Optimize images

*Total -- 320.60kb -> 249.31kb (22.24%)

/resources/img/bulk-ok.png -- 93.70kb -> 69.98kb (25.31%)
/resources/img/email-with-error.png -- 81.07kb -> 62.00kb (23.53%)
/resources/img/bulk-with-errors.png -- 83.10kb -> 64.32kb (22.6%)
/resources/img/email-ok.png -- 39.38kb -> 32.98kb (16.24%)
/resources/img/url-ok.png -- 23.35kb -> 20.02kb (14.25%)

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

Author: ImgBotApp