Fullbright bugfix

[vadiscode]

with gamma mode, the gamma value did not return to the standard

[vadiscode]

i think its better to save the previous value of gamma and then just use it

private float previousGamma;

@Override
protected void onEnable() {
    this.previousGamma = mc.gameSettings.gammaSetting;
}

@Override
protected void onDisable() {
    mc.gameSettings.gammaSettings = this.previousGamma;
}

Great solution!