patches: consider increasing contrast of RW18_1 and 2.

[mc776]

Posting this as an issue instead of a PR because it may well be just a matter of personal taste.

This has bothered me for months now. I've tried to get used to it but it really does feel like the new patch with its very light shadows is out of place in FD:

I know the cracks are intended to be shallow but my brain just Will Not Work With It and instead of a difference in depth it just senses an artistic style clash.

Here's an attempt to increase contrast and gamma while reducing brightness so the overall shade would sorta roughly match:

If folks agree, here are the altered images:

[unithecutie]

Looks a lot nicer, having the details stick out more.

[KorpKat]

Ah, i can see now, yep i approve.