[ImgBot] Optimize images

*Total -- 1,861.29kb -> 1,494.65kb (19.7%)

/Guess the Countries/blank.png -- 854.50kb -> 675.35kb (20.97%)
/Guess the Countries/guessed_countries.png -- 872.34kb -> 689.96kb (20.91%)
/Stopwatch GUI/stopwatch1.png -- 14.60kb -> 12.65kb (13.36%)
/Stopwatch GUI/stopwatch2.png -- 18.76kb -> 16.50kb (12.07%)
/Ghost filter/Images/Real Photo.jpg -- 101.08kb -> 100.18kb (0.88%)

Signed-off-by: ImgBotApp <[email protected]>

Author: ImgBotApp