Remove vignette on new tab page

[shadowsyq]

i was exited to finally add my custom photo to the new tab page, but the vignette over it makes it look not as good. either remove it or add an option to toggle it on/off, as it is making me stick to using the default brave backgrounds. i appreciate the strides being made to increase customizability, but just wish there wasn’t anything getting in my way of doing so!