[ImgBot] Optimize images (#3491)

*Total -- 243.78kb -> 166.94kb (31.52%)

/Website/docs/img/network-interface--bandwidth.png -- 83.87kb -> 51.91kb (38.11%)
/Website/docs/img/wifi--channel.png -- 80.95kb -> 55.24kb (31.77%)
/Website/docs/img/wifi.png -- 78.47kb -> 59.37kb (24.35%)
/Source/NETworkManager.Localization/Resources/Flags/lb-LU.png -- 0.48kb -> 0.44kb (9.53%)

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

Author: imgbot[bot]