Update AltServer AppIcon with BigSur/Monterey Style

[hollow-frenk]

Hi Riley, I hope you like my contribution.

[hollow-frenk]

@rileytestut Is there a small chance to see the altserver icon updated? (Although not with mine)

[hollow-frenk]

@bentoon00 Thank you, but now the colors have changed, can I update the files and keep the status?
Edit: I updated the files with the new colors, but if it's a problem, I can put the previous version back.