Max adaptive level 22 breaks decompressing on smaller machines

https://github.com/facebook/zstd/blob/130c2640d089dc21dd94b4a9056ade641c9c9f1d/programs/fileio.c#L296

I ran into an issue using `--adapt` compression across a network. Not until I started zstd with `-v` did I realize it was going upto level 22 which as the documentation states requires more memory on the decompression side as well, which was breaking the decompression on the receiver side. Setting `--adapt=min=7,max=19` resolved it for this situation.

I think the default max should be set to 19 here.